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How high does the "bug layer" extend? As far as I know, a big obstacle to attaining laminar flow in aircraft today is the so-called "bug layer", presumably a lower layer of the atmosphere where bugs are encountered. So, my question is simply this: how high up do insects stop becoming a serious issue for laminar flow? <Q> In 1961 study a plane flew 116,684 miles sampling the air, catching whatever was up there, and managed to capture a single termite at 19,000 feet. <S> This is the highest ever observed. <S> You just never get above the "bug layer" in a smaller aircraft (Cessna 172 limit is 15,000 feet). <S> Likely this is not a proper naming. <A> I don't have any scientific data, but in my flying experience, including some time back in the 70s in a Breezy , where, as on a motorcycle, you have to be careful to keep your mouth closed <S> , you don't encounter that many bugs above 1000 ft agl (they are there, but few and far between relatively). <S> Descending in the Breezy in a warm summer late afternoon with a low sun angle, you could really start to make out the little back-lit specks in the air up-sun as you descended below about 500 ft agl. <S> It did almost feel like you were descending into a layer of something. <S> In my current airplane, bug spatters on the windshield mostly appear below 1000 ft, although I get the odd one higher. <S> The vast majority of the bug spatters on the wings, nose and windshield happen on takeoff and landing. <S> In the Mooney M20, there is a ram air induction system that supplies unfiltered air to the engine. <S> The POH only refers to "clear air" on when to use ram air, but if you go on Mooney forums where the question comes up, there seems to be a consensus not to use ram air below 1000 ft due to bugs, and preferably above 5000 ft. <S> So it's not really a "layer". <S> If you plotted bug density, you would likely find a parabolic curve with the bulk of the curve below 1000 ft, tapering off above that to effectively zero somewhere above 10000 ft. <A> Yesterday in Oregon I was collecting bugs on my leading edges like a crop duster - at 3500’ AGL. <S> Low pressure, springtime over agricultural fields and vineyards. <S> Mylar balloons are almost as common at altitude in California ;-) <A> Laminar flow isn't necessarily the panacea of design or function; indeed, many aircraft use devices to interrupt laminar flow or energize it. <S> "Bug layer" is a made-up term, perhaps more applicable to the boundary layer than an imaginary atmospheric one. <S> I've hit bugs in freefall around 18,000 and have certainly seen birds much higher. <S> I've hit birds and some large bugs with some frequency above 10,000.' <S> Icing is perhaps more common and a regular occurrence at higher altitudes. <S> Some aircraft are much more affected by boundary disturbances, than others. <S> In the Piaggio P180, even flight through fair weather cumulous clouds at low flight altitudes has a noticeable effect. <S> With the autopilot engaged, it's nearly imperceptible, but when hand flying, requires movement of the control column back and forth, and the change is quite apparent. <S> Likewise, bugs or other interruptions of the boundary layer, including rain or any ice, makes a significant difference in control, speed, and climb performance.
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As already answered, most places it is rare to get many bugs over 1000’.
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How does ATC direct aircraft on ground from the parking to the runway? For medium size airports, ATC will direct aircraft with a single message like this "Taxi to runway 29 via Papa, Sierra". I was wondering if it was the same thing for bigger airports (like international airports) which have a lot of taxiways. I know that if the pilots are not very familiar with the airport, they can ask for controller guidance. But does the ATC can give all the taxiways points like for medium size airports? Thank you <Q> Yes, it's the same. <S> An airport consists of one or several runways, one or several parking areas (aprons) and a number of taxiways connecting them. <S> All runways and taxiways are uniquely named. <S> When taxiing around the airport - be it from runway to parking, or vice versa, or between parking areas, hangars etc. <S> - ATC instructs the pilot of the exact route to follow by specifying the taxiway names in order. <S> ATC can also instruct the pilot to stop and wait at a certain position, or to follow or give way to specific other aircraft. <S> Some airports, in addition to named taxiways, have named holding points around the airport which can be used to specify where the aircraft should stop and await further instructions. <S> Pilots who are not familiar with the airport will have no problem following instructions, since they all have a ground chart (essentially a street map) of the airport layout, with all the taxiway and runway names. <S> Example of aerodrome chart - Copenhagen Airport, reproduced from AIP Denmark <S> Some modern airliners even have a moving map which shows the aircraft GPS position directly on a digital airport map in the cockpit. <S> In addition, signs are posted at all taxiway and runway intersections, showing the name of the current and any adjacent taxiways and runways. <S> Taxiway signs <S> In extreme cases, ATC can make use of turn-by-turn instructions (progressive taxi), but that is very rarely needed. <S> Follow-me/marshall vehicles are also available, but those are usually not to help the pilot find the way, but rather to provide an extra set of eyes when taxiing very big aircraft, to ensure they stay on the pavement during a narrow turn/tight gap etc. <A> What happens in the flight deck at an airport with a complex taxiway system (like NY JFK, which has many multiple parallel taxiways and numerous wrong-turn traps) is the pilot taking the clearance will (should) write it down like a flight plan clearance before reading it back (it's a good idea to write down any clearance with more than 3 elements in it). <S> Before you start to taxi, a crew with good Crew Resource Management practices will than review the clearance and plot the route on the airport chart together, and mutually agree that the route they are taking is the route in their taxi clearance. <S> Then, if there is any doubt on the way to go at any point, call it in to confirm. <S> Such airports have ground radar and know where everybody is on the taxiways, so in the end you can just call and ask directly which way to go if it comes to that. <A> Taxi schemes vary with the airport, and also with the prevailing conditions. <S> Some locations use standard taxi routings with comprehensive airport information that each crew member must be familiar with. <S> Others simplify. <S> Incheon, for example uses green taxiway lights and the crew will simply be given the initial taxi instruction, followed with "follow the green." <S> Green lights illuminate in the taxiway progressively to guide the pilot, and stop bars or hold <S> short indications will be given otherwise, with verbal direction as well. <S> Some international airports can be complex, and confusing.
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Some airports may issue a taxi clearance to a runway with intervening taxiways, while others may issue a taxi clearance to a holding point, and then issue another clearance as the aircraft approaches that point.
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What triggers a CVR to start recording? Until recently, I was under the impression that CVRs will start recording as soon as the engines are started and turn off when the engines are stopped. However, this is not the case given there are only 2 hours of recording time. In one airplane disaster documentary, the CVR started recording at the gate and when the plane was getting de-iced. So when does a CVR start recording, is this something that is started manually? <Q> The CVR (and FDR) are continuously recording while the aircraft is in operation. <S> In the days of magnetic tape, this was done with a continuous loop. <S> In digital systems, the same is emulated by automatically returning to the start of the storage area whenever the end is reached. <S> In both cases, the new data always overwrites the oldest data, so the last N hours is always available. <S> When there is a crash, investigators locate where along the loop the accident occurred, and then read all the way around the loop (physical or virtual) until they reach the accident again. <A> CVRs are normally active as soon as one of the basic electrical buses, like the battery bus, or emergency bus, is energized. <S> CVRs will include a G switch to stop recording in a crash since they record on a continuous loop (most newer ones are 2 hours; older ones 30 minutes) so it can't overwrite the 2 hours prior to the crash if it survived and kept running. <S> They also normally have an ERASE button that the pilot can theoretically push, but he/she would be in a heap of trouble if they pushed it without some really compelling reason if an incident occurred, and some airlines may have specific policies on when they can be erased. <S> Flight Data Recorders, on the other hand, are not started up until some action prior to engine start is initiated, typically when the red Rotating Beacon is activated, which is a standard sign to folks on the ground that you are getting ready to start. <S> On the CRJs, the FDR starts with Beacon, Strobes, or when Weight off Wheels in case you forgot both of the other two somehow, and I'm pretty sure that is typical. <A> By legal requirement, the CVR must be operated from the start of the first checklist (typically Cockpit Preparation or similar checklist), until after the reading of the final checklist. <S> The CVR can only be erased when the parking brake is set. <S> If an incident occurs, some aircraft have a marker button on the instrument panel to mark the event, and the CVR circuit breaker will be pulled to preserve the recording, under certain circumstances. <S> Length of CVR recording may be as little as 2 hours, but most are typically 6+ hours and digital, now. <S> They include area microphones to pick up cockpit sounds such as switches, alarms, etc, as well as microphone channels for the captain and first officer. <S> Regarding a mishap on a 12 hour flight: if the mishap is severe enough to warrant CVR review, the flight isn't likely to continue for another 6-10 hours; it's probably going to be an air turnback to the point of departure, or a diversion to a different airport. <S> A mishap in which the CVR will become significant will occuring up until the CVR can no longe record (a crash, for example); the CVR isn't being over-written, because it's no longer recording.
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The CVR records up to the final moments. So if the airplane has a BATTERY MASTER switch or similar, it is recording audio as you as you switch it on, so pretty much as soon as you climb in and start getting things ready.
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Why did water come into USAirways Flight 1549 if an airplane is sealed and pressurized? Airplanes are supposed to be air-tight and pressurized.However, when USAirways Flight 1549 landed on the Hudson river; water started to come into the airplane. How is this possible if the airplane is sealed? Was there a crack in the fuselage? <Q> Two reasons: <S> They are pressurized using positive air pressure from the engine bleed air and packs. <S> If there is a failure in the system, the aircraft internal pressure will return to the outside ambient pressure. <S> Air will escape the aircraft or enter the aircraft if the outside ambient pressure is greater. <S> Water will react the same way. <S> Especially when you have the combined greater pressure of the water and the atmosphere above it. <S> Combine this with the structural damage caused by the dynamic pressure of the aircraft impacting the water, the aircraft will have ways of water entering the aircraft through burst seams. <S> The structural and hydrodynamic load alone, created by the rapid deceleration of the aircraft will be enough to tear apart the airframe, open sealed doors and bulkheads, and blow out windows. <A> USAir 1549 flooded because the doors opened. <S> Passengers attempted to open the rear doors, worsening the problem. <S> Airplanes are not sealed at all. <S> Not remotely close. <S> They're not air-tight. <S> Pressurization is maintained by varying the air outlet, called the outflow valve. <S> A large volume of air is constantly being pushed into the cabin via the engine bleed air valves and air conditioning packs. <S> A large volume of air is constantly being released from the cabin, meaning the cabin air is completely changed every few minutes. <S> The aircraft doors use seals which are inflated or held sealed by air pressure. <S> The metal door doesn't actually seal; flexible seals around the door do that, and those seals work based on air pressure; when the aircraft touches down, it is no longer pressurized; most aircraft must be depressurized before landing, or depressurized to a minimum differential value, typically no more than .5 psid. <S> In the case of USAir 1549, insufficient time remained to complete the ditching checklist, which included shutting the ditching valve, or avionics exhaust valve, which is done prior to ditching to prevent water from entering. <S> Flotation of the airframe is largely due to air in the tanks, rather than air in the fuselage. <S> The airplane isn't designed to float like a boat, and in many cases, a ditching results in a breakup on contact with the water, as water enters pack inlets and other openings and hydraulically tears the airplane apart like a hollowpoint bullet. <S> The Some aircraft have managed to float for an extended period, but the hope is that it will remain intact and afloat long enough to get out and get away. <A> And someone had opened a rear door that couldn't be closed.
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Airplanes are not completely, perfectly hermetically sealed. There was a hole in the fuselage, and cargo doors had come open.
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Where does fuel from the boost pumps go before engine start? For example let’s take the PT6A-27. In every video related to engine start I see, the fuel boost pump is turned on, and then the fuel pressure goes up. Example: My question is: where is that fuel going if the condition lever is still at the idle cutoff position? Don’t you flood the engine? <Q> I can’t say for sure about the jet engine mentioned. <S> If I think of it like a piston engine, the fuel pump pressurizes the fuel lines. <S> That in no way means that the fuel is entering the combustion part of the engine <S> (cylinders in my case). <S> It just means that the fuel lines leading to the fuel distribution point (carburetor or EFI) are being fed fuel at a certain pressure. <S> A primer is a different story. <S> It is feeding fuel directly into the combustion chamber by using pressure. <S> As mentioned in another post, more pressure and fuel is supplied by the fuel pump than is needed by the engine. <S> In the case of a Cessna 172SP, the excess is routed to a reserve fuel reservoir. <S> Here is a schematic of the fuel system from the POH. <A> On most (probably all) PT6 installations, the fuel pumps send much more fuel than the engine needs. <S> This is true both during operation and before engine start. <A> The pump just creates the pressure. <S> The fuel doesn’t have anywhere to go until you move the condition lever to idle. <S> Think of it like your faucet <S> : There is water pressure there, but it doesn’t flow anywhere until you open the valve.
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That extra fuel is then returned to the fuel tanks.
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Could a flight ever be considered to be operating under Visual Flight Rules and Instrument Flight Rules at the same time? In the US, could a flight ever be considered to be operating under Visual Flight Rules and Instrument Flight Rules at the same time? If not, where in the FARs is this spelled out? Consider the specific case of an IFR-rated pilot flying an IFR-equipped aircraft, but with no IFR or VFR flight plan filed and no IFR clearance requested or delivered, staying in Class G airspace and observing the VFR cloud clearance and visibility requirements spelled out in FAR 91.155 . How can we determine whether this flight is operating under VFR or IFR? Why could it not be considered to be operating under both? Bonus question-- is there any specific case, falling within the general conditions described above, where it would matter whether the flight were operating under VFR or IFR? Assuming that the pilot intends to, and is able to, remain in Class G airspace and observe the VFR cloud clearance and visibility requirements spelled out in FAR 91.155, would it be practical for the pilot to decide in advance that he will simply flip a coin to determine the answer if ATC, or anyone else, enquires whether he is operating under VFR or IFR? With the added proviso that if no one makes such an enquiry, he will leave the coin unflipped until after landing, at which point he will flip the coin to see whether the flight was conducted under VFR or IFR? Would such a plan present any practical difficulties? Related, but not the same-- Can an IFR clearance be issued and flown through IMC in class G airspace? -- note that several of the answers, as well as many comments, to this question also address a different question (which probably ought to be asked as a separate ASE question), which is "May an IFR-rated pilot flying an IFR-rated aircraft in Class G airspace violate the VFR cloud clearance requirements without an IFR clearance?" <Q> No, you can't be both VFR and IFR at the same time. <S> It would be like saying that a ball is both red and blue at the same time. <S> You are either one or the other, never both. <S> If the pilot hasn't received an IFR clearance from flight services, then they are operating under visual flight rules, regardless of their intentions, capabilities, or flight plan. <S> The sole exception is in class G airspace, specifically when they're flying a pre-set departure or arrival procedure from an airport. <S> If a VFR pilot enters a cloud (and there's no emergency in progress), then they are breaking the law, and they can't just decide later that "oh, I was actually IFR at that time". <S> ATC is never going to inquire about which rule set you're operating under unless there's some kind of administrative foul-up. <S> They're the ones that either did or did not issue you the clearance, so they already know which rule set you're operating under. <A> VFR on Top is flying VFR while on an IFR flight plan: <S> What is VFR-On-Top? <S> First things first: it’s ONLY for pilots operating under an IFR flight plan. <S> VFR-On-Top is a request to fly at a VFR altitudes in lieu of an assigned altitude. <S> You must ask permission from ATC to operate VFR-On-Top. <S> Why would you want to operate VFR-On-Top? <S> The most common reason is to avoid bad weather. <S> You may need to avoid turbulence, ice or some other unsavory condition, but the altitude you want is tied up by another aircraft. <S> When the conditions permit (ie VFR conditions) you can ask to fly above the clouds or in between layers. <S> What are the rules governing VFR-On-Top? <S> A VFR-On-Top clearance has its limitations. <S> Here are a few you need to follow: <S> Pilots may not fly below minimum en route IFR altitudes because you could crash into the terrain. <S> Minimum en route altitudes exist regardless of IFR or VFR weather conditions and weather assigned a specific altitude or VFR conditions on top. <S> VFR-on-top is not authorized in Class A airspace. <S> Altitudes as prescribed by 14 CFR Part 91, Section 91.159 must be maintained. <S> Don’t remember 91.159? <S> Here it is from Cornell Law School’s <S> website: CFR <S> 91.159 VFR cruising altitudes or flight level <S> Any VFR cruising altitude appropriate to the direction of flight between the MEA and 18,000 feet MSL may be selected that allows the flight to remain in VFR conditions. <S> Any change in altitude must be reported to ATC, and pilots must comply with all other IFR reporting procedures. <S> The pilot is responsible for traffic avoidance <S> VFR-On-Top is NOT a cancellation of IFR flight plan. <S> You must still adhere to ATC directions. <S> If you can’t stay VFR you must request an IFR altitude from ATC. <A> From my 2-year experience working on flight plans in ATM software, the answer is no. <S> The flightplan must either be VFR or IFR. <S> If the pilot, plane and route qualifies for both, the pilot may flip a coin before submitting the flight plan, but he/she must choose one rule set. <A> 14 CFR 1.1 defines IFR and SVFR as differing from VFR, but doesn't actually define VFR itself. <S> The only explicit statement I can see is 91.101 : <S> This subpart prescribes flight rules governing the operation of aircraft within the United States and within 12 nautical miles from the coast of the United States. <S> In other words, 91 Subpart B applies to all aircraft in US airspace. <S> I'd take that to mean that where it just says "do this" then it applies to all flights (e.g. 91.119 ); if it says "do this under VFR" then it's a VFR-only rule (e.g. 91.159 ); if it says "do this under IFR" then it's IFR-only (e.g. 91.179 ). <S> If you're looking for 'evidence' that VFR/IFR applies to every flight, one place is the FAA flight plan format , which has (had) only three options: VFR, IFR and DVFR. <S> Or the PHAK Glossary , which says "if you can't operate VFR, you must operate IFR": Visual flight rules (VFR). <S> Flight rules adopted by the FAA governing aircraft flight using visual references. <S> VFR operations specify the amount of ceiling and the visibility the pilot must have in order to operate according to these rules. <S> When the weather conditions are such that the pilot cannot operate according to VFR, he or she must use instrument flight rules (IFR) Or the many sections of the AIM, ATC Orders etc. <S> that talk about the differences between VFR and IFR procedures. <S> Maybe someone else will be able to find something more explicit. <A> It's not possible to simultaneously comply with the IFR and VFR cruising altitude requirements, unless perhaps your aircraft is 500 ft tall.
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I can't find any regulation that says "every flight is either VFR or IFR", maybe because it's such a fundamental thing.
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How does a failed turn and slip indicator behave if the gyro isn't spinning at all? I have my own theories, but I have never experienced a turn coordinator or turn and slip indicator's gyro failing first-hand. If the gyro isn't spinning, would the instrument behave like a weak accelerometer but on a different plane of movement, or would it just do nothing at all? For example, would the weight of the motionless gyro of a turn and slip indicator resist movement laterally when the plane is rolled and cause a momentary turn indication from roll or are the centering-springs strong enough to overcome virtually any inertial resistance offered by the weight of the gyro? Another way of asking this is if you held a turn and slip indicator unit in your hand with the display window facing your palm and you rotated (rolled) the unit side-to-side rapidly in sort of a door knob turning motion, would the turn rate indicator needle tilt at from the center position on the display at all? <Q> It depends on how it fails, there are lots of possibilities on what caused it to stop spinning <S> and they can all lead to different outcomes. <S> In this instance it just kind of bobbed around as if it were free floating. <S> But if something is jamming the mechanics it may simply stop moving altogether so it really just depends on how it fails. <A> Turn coordinators have a number of failure modes because they are normally electrically powered and depend on very precise gyro RPM, so the gyro motor runs on fixed frequency 115v ac <S> and there is a teeny tiny static inverter in the unit to convert the airplane's 12 or 24 vdc power to fixed frequency a/c for the motor. <S> Because they are sensitive to bank, Turn coordinators also use an internal damper in the gyro mechanism to filter out small movements. <S> The electric gyro can keep running, but if the damper fails, and it is bumpy at all, the airplane symbol will dance all over the place and you really can't use it (I had one go bad like this, where the gyro still worked but the indicator became hyper-sensitive and moved constantly with the slightest motions of the plane, making it pretty much as unusable as one with the gyro failed). <S> So for an electric turn coordinator, the main failure modes will be an electrical failure in the inverter or a/c motor driving the gyro, failure of the internal damping system, or failure of the bearings. <A> Dave is right in that there are different failure modes that could cause your turn coordinator to behave in different ways. <S> However your ball-in-a-tube slip/skid indicator will not be affected by the failed gyro, and will continue to work.
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If the motor's not running so the gyro is stationary, there will be indications from gyro's mass inertia as the housing moves, but it will be quite random and the needle will randomly tilt and move around.
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Why do helicopter operations avoid IFR? In almost any airplane commercial operation, unless you’re doing something very short haul daytime ops, an Instrument Rating is all but required with airplanes(it’s even in the FARs). Generally the weather won’t stay nice enough for you not to use it, and most airlines and other commercial operations will avoid VFR all together, leaving VFR mostly for recreational pilots. In helicopters however it seems much different. Even in professional settings like news services, 135s Helicopter operations, and even essential services like fire rescue, will try and stay VFR at all costs, and will avoid flying if the weather is not VFR, even if they have an Instrument Rated helicopter pilot. VFR has a lot of limitations that would have a large chance of losing money for a helicopter service. Why is IFR so much more taboo and/or dangerous in helicopters compared to airplanes? <Q> Helicopters do not avoid IFR. <S> They will, however, try to avoid IMC for safety reasons. <S> The same is true for airplanes in the same weight class. <S> Just because the pilot is IFR rated and the aircraft is IFR certified, it does not mean they will always fly IFR, whether they are fixed or rotary wing. <S> Light aircraft in general don’t do well in extreme IMC, whether they are fixed or rotary wing. <S> And, many of the same FARs in Parts 61, 91, 119, 135, 136 and 137 that would require an instrument rating apply almost the same to rotary-wing as they do to fixed-wing. <S> Altitude would be a major factor. <S> The majority of airspace below 1200-1500 feet AGL is uncontrolled airspace. <S> You can not get an IFR clearance unless you are in controlled airspace. <S> Since Part 91.119(d) allows helicopters to operate at reduced altitudes and distances from persons or property, they will specifically be used in applications not conducive to IFR flight. <S> If a helicopter were to fly IFR,they would be restricted to at least an altitude of 1,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown by Part 91.177. <S> This would greatly reduce the usability of helicopters. <S> §91.119 <S> Minimum safe altitudes: General. <S> (d) Helicopters, powered parachutes, and weight-shift-control aircraft. <S> If the operation is conducted without hazard to persons or property on the surface— (1) <S> A helicopter may be operated at less than the minimums prescribed in paragraph (b) or (c) of this section, provided each person operating the helicopter complies with any routes or altitudes specifically prescribed for helicopters by the FAA; and (2) <S> A powered parachute or weight-shift-control aircraft may be operated at less than the minimums prescribed in paragraph (c) of this section. <S> As far as your assertion that commercial fixed wing operations are almost exclusively IFR, that is not a completely true statement. <S> While I will agree with you that may apply to Part 121 operations. <S> That is not necessarily the case for all other operations. <S> Many commercial operations depend exclusively on flying VFR. <A> A properly trimmed fixed-wing aircraft in good conditions could fly upwards of 30 seconds without pilot intervention, whereas a helicopter needs almost continual control inputs, thus leaving less margin for error. <S> To help overcome this risk, the certification requirements for helicopters are more onerous than fixed-wing aircraft, such as stability augmentation systems and autopilots. <S> The effect of this historically has meant only the bigger and more expensive helis were actually IFR capable, so the pool of rotary pilots with IFR experience is much lower than fixed-wing pilots. <S> Finally, the obvious risks associated with helicopter operations - low to the ground, close to buildings, etc - do not work well with bad weather. <S> Here is a really interesting article which talks about these problems in depth. <A> There's another consideration: cost. <S> If you're flying commercially (let's focus on Part 135 to keep it simple), you cannot just "do an IFR flight" <S> if/ <S> when A) <S> the pilot is qualified and current, and B) <S> the helicopter is certified and capable. <S> Just because the FARs say you can, doesn't mean you can. <S> Every operator (no matter what Part) must have an Operations Specification (OpSpec), issued by the FAA. <S> These OpSpecs will go into the minutia on what you can or cannot do, what airports you can or cannot use, if/when/how you can or cannot conduct an IFR flight, etc. <S> (hundreds of pages of this stuff). <S> These OpSpecs are then reviewed periodically, revised as needed, and "continuously monitored" by that operator's POI (Principal Operations Inspector) at the FAA. <S> So, back to the question (kind of). <S> In order to conduct an IFR flight, it must be specifically stated in the OpSpecs that the company can do that IFR flight. <S> In order for that authorization to make its way into the OpSpecs, the FAA must see that the company is maintaining a certain level of training for the pilots and a certain level of maintenance for the helicopters. <S> These are expensive!! <S> The costs of these mandatory requirements are not worth the benefit of being able to do the random IFR flight on those blue moon occasions when your point-to-point flight is going to be going through IMC and you need to get "into the system". <S> It's simply much more cost effective for most helicopter operators to say they just won't do IFR flights, and have that authorization withheld from their OpSpecs.
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Helicopter IFR operations do exist, but the short answer to the thrust of your question is: helicopter IFR is inherently more dangerous than fixed-wing IFR due to the lack of stability. The increased restrictions of IFR flight means that there is much more opportunity to make money in VFR flight with a reduction of risk. The main difference between fixed and rotary wing would be their environments of operation. Specifically, company overhead cost.
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What is the difference between nautical air miles and nautical ground miles? What is a simple way to understand the difference between the nautical air mile (NAM) and the nautical ground mile (NGM)? How does the wind affect the net displacement of the aircraft as that is the only differentiating factor between NGM and NAM? (NAM by definition does not include the vertical displacement or the altitude gained by the aircraft.) For further reference to mathematical formulae defining the above terms: https://www.theairlinepilots.com/forum/viewtopic.php?t=320 From my deep dive in the quest to unravel the mystery of NAM and NGM, with inspiration from the BELOW answers I'm able to conclude with a couple of points: NAM and NGM are same if wind is still NAM measurement is independent of the wind and depends solely on the movement of the aircraft relative to the air around it. NGM is a dependent quantity which solely depends on the wind ie. With a Headwind component NGM is lower than NAM and vice versa for tailwind condition. The usage of NAM was most prevalent in older flight planning systems for long range cruise before the age of FMCs which do the same thing electronically, NAM provides a database of performance of an aircraft in various phases of flight independent of the wind, to which the wind correction maybe applied to determine the practical value. <Q> A nautical air mile is one nautical mile through the air mass. <S> This distance can be different because of wind. <S> For example: If you are flying at 100 knots true airspeed in a zero wind condition, nautical ground miles will equal nautical air miles. <S> However, if you are flying at 100 knots true airspeed into a 100 knot headwind <S> , your nautical ground miles will alway be zero, regardless of how many nautical air miles you fly for (at 100 knots). <S> Anything in between will result in some variance affecting the “net displacement of the aircraft”. <S> This variance can be calculated using the basic wind triangle. <A> How does the wind affect the net displacement of the aircraft...? <S> Before we worry about the definitions of certain phrases such as "nautical air mile" and "nautical ground mile", we should learn to draw the vector triangle of (true) airspeed, wind, and groundspeed , assuming that the flight path, the earth's surface, and the wind are all horizontal. <S> The ratio of miles covered through the airmass to miles covered over the ground <S> is identical to the ratio of (true) airspeed to groundspeed. <S> In the vector triangle of airspeed, wind, and groundspeed-- overlooking for the moment the difference between "true" and "indicated" airspeed-- we can say that the airspeed vector represents the "inherent" performance of the plane, given the position of the throttle or thrust lever, and the position of the elevator control which determines the wing's angle-of-attack. <S> For a given thrust and angle-of-attack, the wind has no effect on the airspeed vector. <S> The plane is flying "inside" the moving airmass and not directly "feeling" the wind. <S> The plane's "inherent" performance won't be enhanced or diminished by the wind. <S> But when we add the wind vector as illustrated in the link above, then we can find the groundspeed vector which shows the actual achieved performance over the ground. <S> As for your implied question about the difference between a "NGM" and a "NAM", the most logical meaning of the "NGM" distance would be the distance coverered over the ground, assuming flat ground, expressed in nautical miles, while the most logical meaning of the "NAM" distance would be the miles covered through the airmass, assuming a horizontal flight path and a horizontal, uniform motion of the airmass, expressed in nautical miles. <S> However, we should be clear that there is no actual difference between the length of a "Nautical Ground Mile" and a "Nautical Air Mile". <S> To make it clear that we are talking about two different quantities of interest rather than two different units of measure , it would be better if we spoke of "distance covered through the airmass" and "distance covered over the ground", rather than "nautical air miles" and "nautical ground miles". <A> Although, I have never heard the term Nautical Air Mile, it does make sense. <S> Based on your attached link, an NAM would be the distance from a particular parcel of air. <S> Airspeed would be the speed at which the aircraft is moving through, towards or away from particular parcels of air relative to those parcels. <S> Airspeed is also the speed at which parcels of air are moving towards or away from a particular relative point or object. <S> Ground distance can be measured directly. <S> So can time. <S> Therefore, groundspeed can be calculated. <S> Groundspeed and airspeed can also be measured through its affect on our instruments relative to the instruments themselves. <S> Measuring NAMs directly seems impractical if not improbable. <S> The most direct way that comes to mind is the movement of radiosonde balloons. <S> Otherwise, NAM can only be calculated from other metrics. <S> I find it difficult to think of any useful application of nautical air miles in practical use. <S> Also of note, in aviation, nautical miles is generally in reference to the distance between two point over which we are flying. <S> Slant range in nautical miles takes into account the straight line distance between the aircraft and a point on the ground taking into consideration the aircraft’s altitude (the hypotenuse of the right triangle). <S> When an airplane’s ground track is affected by wind, its measurement of airspeed vs wind speed is still relative to the ground. <S> But, sense a nautical miles is defined as 1 minute of arc distance of latitude, it makes sense that it would be slightly greater in the air than on the surface of the Earth. <A> These are very strange terminologies. <S> As far as aeronautics is concerned, we care about these things: <S> Airspeed: speed of the aircraft relative to the local air-stream <S> ; this is important for keeping the airplane afloat <S> Ground speed: speed of the aircraft relative to the ground; this is important for seeing how fast you may be getting from point A to B <S> Maybe, ground distance: total distance moved along a [curved] trajectory Ground distance, which could be expressed in Nautical mile, would be an integral of the ground speed. <S> Maybe you can call that unit Nautical ground mile . <S> The integral of airspeed, however, is more or less meaningless. <S> At best, it states how much distance a parcel of air has traveled relative to the aircraft. <S> But since winds change over the trajectory, it wouldn't even be the same parcel of air. <S> The unit of that distance could be what you called Nautical air mile .
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A nautical ground mile is one nautical mile over the ground.
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Why do countries not bound by US law comply with the FAA's originate airworthiness directives? I'm not an aviation or private international lawyer, but is it true that countries unbound by US law, i.e. most if not all countries outside the US, still comply with the FAA's directives ? If so, is the cause merely political and/or public outcry and pressure? Doubtless non-Americans would be worried if their nation state's airline still flew airliners, Boeing or not, against the FAA's directives. <Q> International air travel requires compatible laws at both ends, otherwise a plane might be grounded when it arrived. <S> A web of international agreements therefore exists to implement globally the directives of the major national certificating authorities such as the American FAA and European EASA. <S> Others have been certified by these authorities and do frequent Western airports. <S> The agreements are voluntary. <S> For example the Boeing 737 MAX scandal led many national authorities to reject the FAA's judgement to let it keep flying immediately after the second crash, and to make their own judgements when the FAA re-certifies it, while the EASA has been negotiating hard to ensure that the fixes are also compliant with EU standards. <A> In the case of well-funded, highly-respected agencies such as the FAA and EASA, it makes a lot of sense for other agencies to follow their lead especially when it comes to acting on the side of caution . <S> Any aircraft the FAA or EASA revokes certification for, or demands action for, is at immediate risk of being grounded by other regulatory agencies as these decisions cascade from one agency to another. <S> It's worth it to put the cost of agencies such as the EASA or FAA into perspective. <S> For the FAA : <S> For FY 2020, a total funding level of US$17.1 billion will enable the FAA to achieve its mission while making critical investments that support innovation, protect aviation safety, and make investments in our nation’s infrastructure. <S> By contrast, the government of Namibia (a country with a rather smaller population - well under 3 million people - than the USA's) spent a total of USD 2.3 billion in 2019 , while Namibia's GDP was USD 15 billion . <S> Not only would Namibia gain absolutely no advantage in doing anything other than following the lead of the EASA/FAA, it simply doesn't have the spending power to achieve much in that area anyway. <S> (It remains to be seen whether the FAA's reluctance to ground the 737 MAX has a long-term effect on its international standing as a solid-gold reference for international aviation safety.) <A> Because most countries are signatories to the Chicago Convention which created International Civil Aviation Organization (ICAO) . <S> As signatories they agree (and occasionally agree to disagree) on international aviation standards. <S> This allows for a global aviation industry without every country duplicating every function.
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Some planes made in Russia and China are not able to fly internationally to any significant extent because they do not meet FAA or EASA standards.
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Taxi to spot?? Hot spot? What is meant by this? I heard ground controller at KPHL say taxi to spot so and so?What do they mean by this during taxi procedures. <Q> The word “spot” just means a designated place, or part of the airport where the aircraft is to be parked and shut down. <S> Sometimes they are numbered. <S> Presuming the pilot knows where that is, the controller is simply clearing them to go there. <A> A spot will be just a place on the airport surface. <S> Generally these are termed as specific locations such as the blank ramp for example. <S> A “Hot Spot” is a specific location that is a known hazard for aircraft for one of numerous reasons. <S> These reasons could be from a history of confusing pilots or just from common sense and logic. <S> Some Hot Spots are designated where several taxiways and or runways intersect. <S> They can be Considered hazardous because pilots in the past have confused taxiways for runways and/or runways for taxiways. <S> Some Hot Spots are considered hazardous because Towers view of that area is blocked by obstacles or obstructions. <A> The airport layout is represented in terms of aprons, taxiways, Ramps, gates, bays and sometimes uncommon words like loops, spots etc. <S> The same is very clearly marked on airport charts and is easily locatable if one cares to look. <S> Hot spots are typically intersecting taxiways where there is a possibility of conflict of aircraft on the move. <S> These are also marked on the airport charts and are recommended to be briefed between pilots.
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Known Hot Spots are marked and numbered on some airport taxi diagrams to alert pilots of the hazard.
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What button do I push on the instrument panel to activate DME in VOR navigation? For some strange reason I cannot seem to find any information about what button to push on the instrument panel to active the DME. There is plenty of information about how DME works with interrogation and slant distance, but I cannot seem to locate any information about what button to actually push to activate DME when I am sitting in the cockpit (in a Cessna 172, for example) or where to look on the instrument panel to read the measured distance the DME is telling me. So if the DME is measuring 8 nautical miles, where on the instrument panel will that "8" be displayed? <Q> Typically, there isn't a "button" as such, you tune the DME to the frequency of the ground station (or slave it to the NAV radio). <S> The knob on the right is used to tune a frequency (shown before MHZ) when in "frq" mode, which is usually a VOR/DME. <S> The numbers before NM is your distance to/from the station in Nautical Miles. <A> For the classic DME instrument, see Jamiec's answer . <S> If your aircraft is equipped with a G1000 glass cockpit, the DME window needs to be enabled via the PFD menu using the buttons at the bottom of the PFD: Displaying the DME Information Window: <S> Press the PFD Softkey. <S> To remove the DME Information Window, press the DME Softkey again. <S> The Window will then be shown to the left of the HSI at the bottom of the PFD: <S> DME INFORMATION WINDOW <S> The DME Information Window is displayed above the BRG1 Information Window on the 360° HSI and in a box above and along side the Arc HSI. <S> It shows the DME label, tuning mode (NAV1, NAV2, or HOLD), frequency and distance. <S> When a signal is invalid, the distance is replaced by -.-- NM. <S> Refer to the Audio Panel and CNS Section for information on tuning the DME. <S> Source: Garmin G1000 Manual - Cessna <S> Nav III <A> Both Jamiec’s and Bianfable’s answers are right for the avionics equipment represented in their posts. <S> Your actual answer will depend on what equipment you have in your aircraft. <S> In my own recent experience, I have not seen an operable DME radio in a Cessna 172. <S> I’ve only seen one operable ADF in a Cessna 172. <S> In most cases, they will look like smaller versions of your NavCom radio. <S> Mainly, I see at least one of the NavCom radios retrofitted to a GPS unit like the Garmin G430 or G530. <S> This is a preferable expense than maintaining technology that is becoming increasingly obsolete. <S> And, per AIM 1-2-3, RNAV/GPS can be substituted for DME. <S> If you are flying a glass panel aircraft like one equipped with a G1000, G500, or Dynon Skyview, the GPS distance to your selected point will be displayed on your PFD and is an option on your MFD. <S> This can be found in the top info bar of your PFD. <S> As long as the position of the NavAid is updated in your GPS database, you can select it as a fix and use this distance for navigational purposes.
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Press the DME Softkey to display the DME Information Window.
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What are pro/cons of steam as lifting gas for airships? I was reading Wikipedia page about hot air airship and another Wikipedia page about the first powered and steerable airship which was powered by a steam engine. So I ask myself "why didn't they use the exhaust steam from the steam engine as lifting gas?" After quick research, I found this home made experiment of steam used as the lifting gas. This website even gives a comparison with other lifting gasses: +-------------+----------+------------+-----------------+--------------------+--------+-----------+-------------------+------------------+| GAS | M.W. | Temp. (°C) | Density (kg/m 3 ) | Lift (N/m 3 ) in ISA | Safety | Cost | Ease of provision | Buoyancy control |+-------------+----------+------------+-----------------+--------------------+--------+-----------+-------------------+------------------+| H2 | 2 | 15 | 0.084 | 11.19 | bad | fair | fair | no || He | 4 | 15 | 0.169 | 10.36 | good | very high | very bad | no || CH4 | 16 | 15 | 0.676 | 5.39 | bad | low | fair | no || NH3 | 17 | 15 | 0.718 | 4.97 | fair | low | fair | no || hot air | 29 (avg) | 110 (avg) | 0.921 (avg) | 2.98 (avg) | good | very low | good | yes || steam (H2O) | 18 | 100 | 0.587 | 6.26 | good | very low | good | yes |+-------------+----------+------------+-----------------+--------------------+--------+-----------+-------------------+------------------+ (source: http://flyingkettle.com/jbfa.htm ) Given the conclusion of this website, steam should now be more widely used as a lifting gas: it is available since the first lighter-than-air (plenty of time to develop the technology) it has a good lifting power it is cheap and safe Yet, on 2020, almost all airships and balloons use helium or hot air, and no other lifting gas. So there must be drawbacks I fail to imagine. I hope finding those drawback will orient my research for my first question ("why didn't they use exhaust steam as lifting gas on airship fitted with steam engines?"). Moreover, there may be advantages I also fail to imagine. Thus, what are pro and cons of using steam as a lifting gas? <Q> The main disadvantage is the energy required just to get off the ground. <S> Let's do a back-of-the-envelope calculation, comparing this to a hot air balloon. <S> Let's heat 1m³ of air. <S> To get equivalent lift, we need about 0.5m³ of steam. <S> The density of air is about twice the density of steam. <S> So, for a given amount of lift, we need to heat approximately the same mass of lifting medium. <S> To heat 1kg of air to 100°C above ambient, we need about 100kJ (specific heat of air is about 1kg/(kJ K)). <S> To heat 1kg of water to 100° above ambient, we need about 420kJ just to heat the water. <S> To vaporize the water, we need an additional 2250kJ, for a grand total of 2670kJ. <S> The most used hot air balloon size is 2800m³. <S> For that we need to heat 1400kg water. <S> Multiplying gives about 4GJ of energy or 75kg of propane just to get off the ground. <S> Since we established steam can lift twice as much per unit of volume, we can maybe get away with 2GJ or 35kg of propane. <S> Some more negative thinking... <S> Condensation on the outer shell seems like a very efficient mechanism to transport heat energy to the environment, only partially offset by the reduction in surface area compared to a hot air balloon due to the cube-square law. <S> This may require more energy in flight than a hot air balloon. <S> Closed-cycle operation (only heat condensed water, not 'new' water) is preferred due to the high energy requirement, so descending means you have to wait for enough water to condense or be willing to pay the price in fuel. <S> Superheated steam is not safe (despite what your table says); the high heat capacity and enthalpy of condensation can result in serious scalding burns compared to hot air. <S> All of these effects are of course much more pronounced when comparing to a helium-filled blimp. <S> Still, it's a really neat idea, and sometimes you don't need a practical reason just to build something neat. <A> In short, helium (or hydrogen) remains in the gaseous state at much, much lower temperatures than water does. <S> In particular, helium or hydrogen will remain gaseous in pretty much any part of Earth's atmosphere. <S> Water, on the other hand, will not naturally remain gaseous in any part of the Earth's atmosphere. <S> On the contrary, it will freeze in most of the Earth's atmosphere. <S> You can aid this by insulating the airship really well, but you can't bring the heat transfer down to zero. <S> And this will also add a significant amount of weight, reducing efficiency further. <S> Additionally, as Sanchises's answer mentions, it takes a large amount of energy to turn that water into steam in the first place. <S> Water has a very high specific heat and also a high enthalpy of vaporization . <S> That is, water takes much more energy per unit mass than most substances to heat up and also more energy per unit mass to convert from a liquid to a gas. <S> So, you're requiring a very large amount of energy to get the water into the gaseous state in the first place <S> and you then need a large and continuous energy source to keep it there during flight. <A> Lighter than air balloon works by replacing air with some gas that is lighter than air . <S> Your steam airship would work if we can keep steam at 100 C or higher or else you risk condensation, your balloon collapse into some saggy bag and you fall out of the sky. <S> Wikipedia mentions that when water turns into steam it expand 1700 times so imagine, in reverse, your 1700 cu.m. hot steam balloon when cool down and becomes 1 cu.m. bag of water <S> and you lose all the lift. <S> That does not sound safe at all. <S> Consider low temperature up there <S> you need a lot of energy to combat heat loss through conduction over a large surface area of the gas bag. <S> To sum it up you need lots of energy to keep the balloon in positive buoyancy and a big safety issue to solve when that energy source fail. <A> In addition to the tremendous energy requirements, you'd need a highly specialized design that is not at all bothered by boiling hot water dripping back out of the balloon. <S> Even if it was highly insolated, you'd need to be resupplying steam to keep the balloon inflated because even small amounts of local condensation would pull a lot of water out of the air because water expands so much when it becomes steam. <S> Even like, a cup of water running back down the balloon over the course of the entire voyage would be over 100 gallons of steam. <S> This in general would be hard to build, fuel inefficient and difficult to control while being wildly dangerous. <S> They didn't use exhuast steam because the efficiency of a balloon isn't acheived by min/maxing the displacement of air by any means possible. <S> It is acheived by realiability, cost and control. <S> Blasting a second gas as a by product of the steam engine, doesn't improve that in the slightest, and likely would create problems.
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For steam to remain steam, it must be constantly heated to make up for the energy it's losing by heat transfer to its surroundings.
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Single vs Twin motor for an electric RC airplane I'm designing a fixed wing UAV for a project. I need an airplane that can fly for at least 200 minutes. Obviously, it means a big battery and thus a lot of added weight. I've been debating whether or not I need a twin motor configuration. The idea came after I saw a video of a modified "My twin dream" airplane that has a range of 269 km and can fly for more than 5 hours. The extra thrust might be the reason it can fly for that long but I can not find any research for electric twin motors whatsoever. Let's say the cruise speed would be 15 m/s. If it only has one motor, maybe it would need to run at 90% of its power vs if it has two motors they would need to be at 45% of their power to match the required thrust for that cruise speed. This could mean, two motors are more efficient than one, even though the extra weight of the added motor. I'm not sure how to solve this problem. <Q> You should keep in mind that adding an engine adds wiring, extra propeller (a larger single prop might to be lighter in RC than an equal setup of two), overall complexity etc. <S> As I understand it, electric motors have a "sweet spot", or rather an area of (iirc) certain load and rpm. <S> You should desing your configuration so, that the motor(s) would operate in this rpm/load range in cruise. <S> This sweet spot is (again, iirc) much higher than half load. <S> So it is likely you are better of with a single engine than two that are only utilizing about half their rated pwr. <S> This sweet spot is very motor specific, so you need to dig deep into spec sheets. <A> Your intuition is right, that aircraft design, large or small, is a mess of tradeoffs. <S> One way to experiment with such designs is software such as the venerable Motocalc , which lets you choose the airplane's attributes (minimum flight duration), some constraints on its design (up to two motors, weight range for batteries, etc.), and then gives you many designs that optimize your attributes. <A> The single prop should be more efficient if both systems are designed properly. <S> My understanding is that the benefit of a twin on UAVs is ease of mounting the payload <S> (counter-rotating props is nice too). <S> Note that one larger propeller is more aerodynamically efficient than two smaller ones totaling the same area. <S> That is a big drawback in efficiency for using two electric motors instead of one. <S> From the RPM-efficiency curves I have seen for DC motors, and from what I have read, the efficiency tends to peak at right around 1/7th the no-load RPM while the power peaks at 50% no-load RPM. <S> Better to load it a bit too much and have it run a bit slower than load it a bit too little and have it run faster since the slope on the side that is underloaded drops off much faster than the slope on the side that is overloaded. <S> If you want to get peak efficiency when it occurs at such a high RPM combined with the efficiency of large propeller, you will probably need a gearbox. <S> Gearboxes are expensive so you probably don't want two of those. <S> If the mission profile allows, you might benefit from designing the motor-prop for maximum efficiency during a climb and then operate it to repeatedly climb and descend in an unpowered glide rather than design it for maximum efficiency in cruise and then cruise under power the entire time. <S> Designing things for optimal efficiency during climb and then operating like a sailplane lets you use a motor-prop combo that is better suited for takeoff while also enabling you to only ever run it at the point of optimal efficiency during travel.
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A motor-prop combo designed to be most efficient during cruise will produce just enough thrust to overcome the drag so that it can be running the entire time with no efficiency penalty, but such a combination will probably have a lot of trouble getting off the ground.
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Why landing gears still need bungee springs? While studying landing gear, I came across this term 'bungee spring' to which there was no definitive explanation in text with regards to its usage. So in the image, you can see for the jury strut/ drag brace down lock strut there are 2 bungee springs used even after the presence of downlock actuators. As per my assumptions they must be used to give the jury strut some extra kick while extension and gravity extension and improve redundancy or there's some other reason? <Q> The key to this is the text in yellow in the bottom right-hand corner Lower torsion link (Disassembled) <S> It will be removed when the work is complete and the lower torsion link reassembled. <A> The purpose of the (bungee) cord was correctly explained by CatchAsCatchCan... <S> however If the question is about the springs, their purpose is to help pull and lock the drag strut into <S> it's down position. <S> Once the drag brace jury strut reaches the level position in picture, the spring load is enough to keep the landing gear from collapsing under any "normal" external load in any direction. <S> Only way to retract the gear is to release the drag brace jury strut from it's locked position by pulling it upwards with the drag brace strut actuator. <S> Should the actuator fail, gear lock will be achieved and maintained by the springs alone. <S> Please note there is a similar arrangement in the strut seen in the behind. <S> The spring is brought outside the strut via an extension to the jury strut, and is therefore pulling upwards to lock the jury strut. <A> The drag brace strut is an "overcenter" locking strut. <S> It has a "knee action" to provide a kind of passive locking function because when moved into its overcenter position, compression forces <S> a can only try to overcenter it more, which is prevented by the contact lugs above the center pivot and it can only fold going the other way. <S> It works the same way as your knees when standing. <S> You can keep your knees bent slightly so that your weight is trying to fold your legs up. <S> If you bring your knees back while standing as far as they will go, they "overcenter" and your weight can only try to make them overcenter more, which is prevented by the bone structure of your knees. <S> So when you stand up from a knee bend and your legs go into that overcenter lock mode that allows you to relax your thigh muscles, your legs are "down and locked". <S> While standing like that, some trickster might come along and bump your knee from behind and break the overcenter, making you start to fall before your thigh muscles can take over. <S> Or someone could lift you up just enough to let the compression load on your legs be released and then let you go, and might find that your knees moved forward of the overcenter axis as your weight comes back down on them, and down you go before you thigh/butt muscles take over. <S> The springs are there to prevent that in the case where temporary tension is applied when the gear comes under load, bringing the strut out of overcenter to on-center; when compression is re-applied, without the springs it could go either way, back into overcenter or out of overcenter, and collapsing, like your legs. <S> The springs guarantee that the brace will always move back to the overcenter position unless forced out of it by the drag brace actuator. <A> If it is the actual steel springs we are wondering about, a thought about "convertible" sofa/beds came to mind today. <S> Clever use of springs make these 300 lb items very easy to unfold. <S> Springs can be placed, with the proper leverage, to help lift or move a heavy object by opposing most of its weight, with enough weight left to keep it in place. <S> The counter weights of a "dumb waiter" or elevator work on the same principle. <S> This would serve to make the actuators much smaller and lighter, a big plus on aircraft. <S> Springs or "bungees" could be interchangeable, especially on smaller aircraft, but steel, especially for repeated cycles, may be favored.
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The bungee is simply being used to support part of the mechanism that is being worked on.
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Do pilots keep light in the cockpit during long night flights? During long times of the cruise flight, is the internal light normally switched on or off inside the cockpit? Knowing it is generally dark in the night would make a smartphone-based night time logger easy to write. <Q> Red lights are sometimes used as these do not impact night vision. <S> One of the challenges you'll run into is knowing when it's night, as the start of night varies by latitude and the exact time. <S> Phones generally set their time from the mobile network, which may be absent on long flights, especially those over water. <S> A pilot flying a jet over the pacific may may have a phone that is hours off the local time. <S> Putting my (albeit old and tattered) mobile developer hat on I would suggest you look for ways the phone can tell you whether it thinks it is night or day and use that, plus a manual selection for day/night mode. <S> Look at the Android UIModeManager as a way this could be done native. <A> If you are asking about logging night VFR -time, you are not concerned with lighting conditions. <S> Night time is logged according to regulation based definition of night (at least EASA), tables for night time are usually available from local aviation administration websites. <S> Your logger simply needs to know your position, date and time, and refer to the official table or definition of night if table is not available. <S> EASA defines night as " ‘Night’ means the period between the end of evening civil twilight and the beginning of morning civil twilight or such other period between sunset and sunrise as may be prescribed by the appropriate authority, as defined by the Member State." <S> Not quite as informative as one might like, but this is how thing work in avaition... <A> To strictly answer the title question, at least in GA operations, we typically fly with the cockpit lights off to avoid ruining our night vision. <S> We do sometimes use red lights to see stuff in the cockpit, though. <S> However... <S> It's unlikely that a photosensor will be very useful for determining which hours count as day vs. night. <S> Lots of factors will affect the relationship between time of day and received light on a photosensor in the cabin. <S> These include, but aren't limited to: position, altitude, heading, orientation of the phone, latitude, time of year, weather, etc. <S> This is compounded even more by the fact that what counts as "night" varies, not only by country, but even within the same country depending on the purpose in question! <S> For example, according to this AOPA (Aircraft Owners and Pilots Association) article , the US FAA definition of 'night' for purposes of logged flight time for private or commercial certification is the one in 14 CFR 1.1 : <S> Night means the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac, converted to local time. <S> It's highly unlikely that you'll be able to figure that out with a photosensor on a phone in the cabin. <S> You'll instead need the aircraft's location and time (and the formulas for figuring out when civil twilight starts and ends.) <S> However, for purposes of being 'night current' in order to be allowed to carry passengers at night, the definition of night is defined differently in 14 CFR 61.57(b) : <S> the period beginning 1 hour after sunset and ending 1 hour before sunrise <S> Indeed, it turns out that the FAA uses several different definitions for different purposes, as described in detail in answers to the question <S> How does the FAA define day and night? <S> And that's just the U.S. <S> So, what you'll really need to solve your problem <S> is: <S> Aircraft position Time <S> The relevant rule for whatever purpose you're wanting to know about day vs. night. <S> Thankfully, the first two should be easy with a modern smartphone. <S> At least for the U.S. definitions, local time should be irrelevant. <S> Your phone's system time (in UTC) and position should suffice, so crossing time zone boundaries shouldn't matter.
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White lights are usually off in the cockpit in night flights to protect pilots' night vision.
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Do aircraft at cruise bob and/or skip? Recently I started flying a model aircraft, admittedly a kindness for a motor stuck onto a piece of foam, and have noticed that it either bobs, for lack of a better term, like something afloat on water might when depressed or that it skips, for lack of a better term, like a stone thrown across the surface of a pond might. In the first case the motorized foam is at cruise at constant speed at some height when I force it into a dive it seems to "bob" back up to it's original height when I stop giving it the input to dive. I suspect I'm observing a little Newtonian mechanics here trading potential energy for kinetic energy during the dive and that this gets converted back as it "bobs" up again. In the second case when the motorized foam is at cruise at constant speed at some height it tends to undulate. This is exacerbated if I increase the angle of attack(?) such that in the extreme, where it stalls, the motorized foam goes into a cycloidal "swoop". Each "swoop" starts with a stall where it'll "flip over" and dive down and gaining speed as it does so, the gain in speed results in the nose "picking up" resulting in a "swoop" back into a near vertical "climb", at roughly the same height as when it first stalled it'll stall again and repeat the process. Do larger scale aircraft, that is anything with at least a human on board, behave in this manner as well? In the case of "bobbing" do pilots use this in any way to their advantage e.g. does it help them maintain altitude or is it helpful in some way during dire situations? (My imagination can't help but wonder if there was ever a pilot who forgot to throttle down on decent, intending to land, who found they simply "bobbed" back up to their pre-decent altitude?) In the case of "skipping" I can't imagine passengers being very agreeable to such a motion, especially not the stalling swoop variant, but I'm fairly certain I've felt a plane undulating slightly on a flight before. Do pilots have to constantly fight such undulations or do they reduces/eliminate this through proper trim? Note: I'm not talking about wing in ground effect, I observe this when the motorized foam is at roughly tree top height. The veldt I fly in comprises of knee high grass so I doubt I'll observe this until I fly over a lawn or something. Note: If it's relevant motorized foam is shaped like a flying wing; in case aircraft with tails behave differently. Note: I've certainly observed that the wing tends to "pitch up" in proportion to its speed above a certain speed; this is most noticeable in the cycloidal "swooping". Initially I thought this was a CG thing or that the motor was off center and generated a moment force but I see this is already discussed . It's more likely my trim is off. Update Update : I phugoid it out, I believe, stuck a coin under the battery (rotating it made it poke out like an Adam’s apple) and I trimmed the trim to something slim. Did the glide test and she stays level as a lake wafting gracefully from the skies like Dumbo with his trunk out, tail tucked and his C.G. Is under his chin ! Thanks all for the helpful hints and the epoxy related non-confessions. (When the coin is worth more then the model I’ll fork out for an upgrade. Till then I’ll wait for the back of this cold front) <Q> It sounds very much what you're experiencing is a Phugoid cycle Image License info To put simply, your aircraft is not trimmed correctly. <S> As it descends slightly it gains speed, which increases lift over the wing making it climb. <S> This has the effect of it losing some speed, reducing the lift over the wing causing a descent, increasing the speed - and on it goes. <S> Full scale aircraft from light to airliner can and do experience the same thing. <S> One notable case which comes to mind is the accident sequence of United Airlines 232 which lost all hydraulic pressure and thus had no control surfaces operational. <S> They were controlling pitch (and roll) somewhat using engine power only, and thus did not have exact control of pitch and experienced significant Phugoid cycles. <S> Side note: <S> You're unlikely to be experiencing ground effect at treetop height unless you have very tiny trees or very large wings. <S> When an aircraft flies at a ground level approximately at or below the half length of the aircraft's wingspan there occurs, depending on airfoil and aircraft design, an often noticeable ground effect source <A> If there ever was a pilot who forgot to throttle down on descent Full scale pilots trim their elevator for speed, and use their throttle to climb or descend. <S> "Bobbing or skipping" behavior in cruise is a sign of instability, not surprising for a tailless piece of foam. <S> If this plane has a published CG location, thrust angle and control surface throws, start there. <S> If you have a hill nearby, power off glides will help determine if your CG is OK. <S> If you are nose heavy, the plane will dive to a higher than desired glide speed and require a lot of up trim, but should not constantly pitch up and stall. <S> Moving weight forward generally improves directional stability. <S> If you are tail heavy the plane will be more difficult to control and tend to pitch up sharply with speed, sort of what you are seeing. <S> So work with weight first, in small increments . <S> You want a slight tendency to pitch up with increased speed in glide so it can self control its speed. <S> After you get it gliding stably at a speed comfortably above stall... <S> Make sure your control throws are not too much or too little, then ... For powered flight, you want your thrust angle slightly down to help counter act the pitch up tendency at higher speeds. <S> Just a few degrees, again adjusting at small increments. <S> Models tend to be overpowered, this may take a few tries. <S> The plane should track level or climb a bit when throttle is applied, without excessive trim required (some is normal). <S> Planes with tails generally are more stable in pitch, but even these will "bob" if they are not set up properly. <A> In my experience with model airplanes the bobbing and dipping motion occurs when the center of lift is forward of the center of mass and represents a series of mini-stalls and recoveries that persist and repeat. <S> Back in the day, all my free-flight rubber-powered kit planes were set up to make this pitch trim adjustment easy. <S> If you go too far and move the center of lift too far behind the center of mass, then the plane immediately plunges into a nosedive.
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Since simple model planes generally do not have elevator trim, the solution is to move the wing attach point aft in small increments until the plane does not "do the dip".
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Are there any remaining flying boat or seaplane airliners in operation? Is there anywhere in the world that still offers scheduled air carrier service using flying boat / seaplane types of aircraft - something akin to a proper airliner? Or are they all limited to charters and shuttle-type flights on de Havilland Otters and the like? <Q> The flying boats that are still in commercial operation are typically used for fighting forest fires or maritime patrol. <S> This may change in the near future since there are currently at least two flying boats in development that might be used by airlines: Dornier Seastar CD2: <S> This is a newer model of the previous Seastar , which had its first flight earlier this year: <S> Dornier Seawings flew its new-generation Seastar amphibian for the first time on 28 March from its base in Oberpfaffenhofen, Germany. <S> [...] <S> Dornier says the aircraft will be offered in various configurations including cargo, passenger , special missions and VIP transport. <S> ( flightglobal.com , emphasis mine) <S> AVIC <S> AG600 : This is new aircraft developed in China and one of the biggest flying boats ever. <S> It had its first flight in 2017 and according to Wikipedia is expected to be delivered by 2022, possibly also in a passenger variant: <S> Further variants may be developed for maritime surveillance, resource detection, passenger and cargo transport. <S> If you are not just interested in pure flying boats, but also floatplanes , then there are many airlines world wide that operate these on regularly scheduled flights. <S> One of the biggest is Trans Maldivian Airways operating various variants of the DHC-6 Twin Otter. <S> They operate 55 seaplanes, which according to Wikipedia makes them the biggest seaplane airline: <S> TMA currently operates the world's largest seaplane fleet. <S> They offer flights to over 80 destinations: <S> Trans Maldivian Airways currently offers transfer services to more than 80 Maldives resorts, flying over 1 million passengers per year to their holiday hideaways. <S> ( transmaldivian.com ) <S> This is their main terminal at Velena International Airport: <S> (image source: Wikimedia ) <A> Last time I was there (fifteen or so years ago) there was a thriving commercial air passenger operation, including at least a couple scheduled flights (weekly, I believe, not daily), at the north end of Lake Washington (near Seattle), officially in either Bothell or Woodinville, Washington state (comments reminded me <S> it's Kenmore Air, in Kenmore, WA). <S> There were no flying boats in service there, but there were Beavers and Otters on floats. <S> Beyond that, there are a number of tiny (one or two aircraft) airlines operating scheduled feeder service in Alaska and northern Canada that operate on floats, because lakes and rivers are much more common in the wilder parts of the sub-Arctic and Arctic than even grass or gravel airstrips. <S> As long as there's water to land on at both ends, such aircraft are good to go (and some have retractable gear, so they can land on concrete if necessary) -- and if you're starting from a village equidistant from Fairbanks and Nome, these are likely to be your only choices for local service. <S> The bulk of their revenue is likely from hunting and fishing charters, like any bush operation -- but many of them operate weekly or twice-weekly scheduled flights to a hub terminal. <A> There is at least one jet flying boat, the Beriev B-200 , in production. <S> The Wikipedia article gives it a capacity of 72 passengers. <S> I don't know how many (if any) are employed in an airliner role, though this variant has a "pressurised and air conditioned cabin allowing transportation of up to 72 passengers. <S> The passenger variant is the BE-210 shown here at beriev.com <S> Most seem to be employed as water carriers in a firefighting role; it was designed to skim the surface and scoop up water at close to takeoff speed. <A> Four or five years ago or so, Pacific Coastal Airlines spun off its seaplane division as Wilderness Seaplanes , which flies scheduled service in a fleet of four Grumman Gooses in British Columbia. <A> Not "air carrier service", but Viking Air acquired from Bombardier the type certificates and continues to produce the CL-215, CL-215T, CL-415 and CL-415EAF as an aerial firefighter , an amphibious aircraft. <S> Again, not "air carrier service" but a true flying boat, Coulson Flying Tankers effectively grounded the last Martin Mars water-bomber in 2018. <S> They are fondly missed. <S> The following relates to "Float planes", rather than "flying boats or seaplanes" ... <S> Viking Air also hold the type certificate for the legendary De Havilland DHC-2 <S> Beaver <S> DHC-3 <S> Otter and DHC-6 Twin Otter . <S> A refreshed, next-gen specification Twin Otter - series 400 is now back in Production. <S> From their website, With a fleet of 57 de Havilland Twin Otters, Trans Maldivian Airwaysoperates the largest seaplane operation in the world. <S> TMA is the airline referenced in @Bianfable 's answer. <A>
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NORDIC Seaplanes flies daily between the two largest Danish cities. As far as I know, there is no actual flying boat in use at an airline.
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Is PVC tubing a good material for helicopter airframes? Been thinking of getting into the hobby of building ultralight helicopters, and would PVC tubing be a good choice to build the overall airframe? <Q> No. <S> The strength to weight ratio of PVC is poor compared to aluminum <S> and you would end up with a very heavy, albeit cheap, machine, and will be even worse when compared to carbon fibre tubing, which would be the optimal choice performance-wise. <S> Extruded aluminum tubing would likely be the best choice cost wise. <S> Forget about building a plumb-O-copter. <A> And its strength to weight ratio is poor. <S> The structural efficiency of air machines is absolutely critical otherwise you are building a machine that may not fly at all. <S> Plus, do a search for helicopter ground resonance, especially watch some youtube videos of helicopters destroying themselves. <A> In my experience using PVC to build scale models, PVC doesn't make a good construction material: <S> it's too flexible. <S> PVC pipe will bend under its own weight. <S> the glue typically used to join PVC is pretty weak, impact loads will break the bond.
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PVC is no where near stiff enough for a given weight.
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How can I easily keep track of my landing count during pattern work? PPL Student pilot, ~20 hrs Hi,whilst doing some pattern work I frequently find myself unable to keep accurate track of the number of landings. There's an AFIS at my home airport who keeps track (because they charge fees) but there are a few "flatrate" (you pay for 5 landings, but it's flat-rate after 5) air fields or some free gras strips where nobody keeps count. The flat-rate one is particularly hard, the pattern altitude is just 650 ft and it's very tight, so there's barely any chance even on the downwind to scribble a note on paper or so. I've tried using a "lap timer" function on my watch, scribbling lines on a tally sheet etc, but am prone to forget to add a line when things get busy. My multi-tasking capability hasn't improved to the point where I can do too many things at once.An extrapolation of flight time and time per pattern isn't always giving me the correct answer either. Would the Pros have any tips on what might be a useful way to keep an accurate count of the landings? How are you doing that? Update 14/07/2020 Based on the @Bianfable's tip, I've installed "Altimeter Plus" on Android, and had that active. I thought I'd share the results with you: My problem is solved. I've flown 11 patterns, which are clearly visible (marked yellow). I've done two engine failure after takeoff trainings, marked blue. The red marker must have been a sensor error; I don't remember crashing between the first and second landing. The green markers are forced landings w/o power, aborted at about 350 feet each. The bad thing about it: Although it was gusty and there were strong winds, I can now see that my altitude control could be improved in the pattern. I don't ever remember being more than 50 feet off, but the data suggests otherwise.Once again, fabulous tips all, but this was the winner. Phone in my pocket keeps count, and provides reprimands to beat oneself up about after landing. Great! Even provides pretty accurate flight time, next time I'll try and activate it on top of the hour for easier calculation of what time second "x" actually is.Next time I'll also have phyphox running and will measure the acceleration on landing. The next thing to improve... <Q> The trick my CFI taught me is to use your Course Deviation Indicator or ADF to keep track of landings. <S> After your first landing, bug a course of 010. <S> After your second landing, bug 020. <S> You can reach over and adjust the knob after every landing without having to juggle a pen and a notebook. <S> It's still a manual step, though. <A> The other answers have provided some easy ways to increment your count without too much distraction, but if you are really "prone to forget [...] <S> when things get busy" as you say, this might not be good enough. <S> I would therefore recommend a solution which does not require any action on your side. <S> Most smartphones today have a pressure sensor . <S> e.g. this one ). <S> All you have to do is start the recording before you go flying and then later look at the pressure vs. time plot. <S> In an un-pressurized aircraft it will be easy to see your landings (these sensors are typically accurate enough to tell the difference between your feet and your head). <S> Alternatively, you could record your GPS position over time (e.g. this app ) and look at your flights that way. <S> Note that both of these options would work even with the phone in flight mode. <A> Get a Tally Counter, and push the button once per landing. <S> No batteries, nothing to fail, easy to use. <S> Not much more you could ask for. <S> https://tallycounterstore.com/finger-tally-counter-quantity-discounts/ <S> There are even options for mounted ones. <S> https://tallycounterstore.com/mounted-tally-counter/ <A> (Disclaimer: I'm not a pro at all, I don't even have any license yet) <S> If you do indeed have a smartphone with you, you might consider just letting a voice recording run for the duration of your pattern work and call out your landings. <S> When you're back on the ground, you can just listen through the recording and count the landings. <S> This might also have another interesting use, as you could actually comment on your maneuvers, i.e. if you're happy or unhappy with something, so you could analyse it later. <S> Afaik, Flight Chops (the aviation youtuber) initially started recording his flights on camera in order to be able to analyse them later, so that might be a way as well. <S> (Also, welcome to aviation.stackexchange ) <A> Almost every calculator can be converted into counter just by typing something like 1 + = <S> (and then every time you press = the value is incremented). <S> This can be used if you need aircraft instruments for the training itself instead. <A> Pace count beads , which are just some beads on a rope that doesn't let them readily move, would work well if you want to keep track while in the air. <A> I use my ADF. <S> Set the frequency to 1000 when I start, bump it by one for each landing. <S> (Might as well use it for SOMETHING!) <A> I asked my CFI this after a day where we did over a dozen landings. <S> He showed me his kneeboard notebook - there was a neat little row of tally marks next to the METAR info for each field we'd landed at. <S> The trick he used was that he was marking takeoffs , because ultimately what takes off must land (note; this won't work for spaceplanes). <S> During the climb you're really just holding it steady and listening for calls; I find in a c172 that's a good time to grab the pen and make a mark on the kneeboard.
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You could also use a product like Foreflight or CloudAhoy or even a service like ADSBExchange to count the number of approaches you made after the fact. There are apps that can record the pressure data over time (
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Is the APU classified as a component of Airframe or Powerplant? In the classification of systems and components on the aircraft - is an APU classified under the Airframe or the Powerplant? <Q> I was a tech writer in another life. <S> Under ATA100/2100 , the Air Transport Association system of categorization of systems for maintenance manuals, the APU is Chapter 49 (Airborne Auxiliary Power). <S> Power Plant chapters are 70 and up. <S> (Some OEMs also use a equivalent numbering convention for engineering drawings to align them to ATA100/2100, where, say, if Flight Controls are Chapter 27, flight controls related drawings would have "27" at the start of the drawing number with the applicable sub-system numbering as appropriate - makes finding drawings in a database quick and easy). <S> Airframe systems are Chapters 20 thru 50. <S> So from that standpoint, its Chapter 49 designation makes the APU an airframe system, not a Powerplant (which only refers to propulsion engines per ATA), as far as the industry is concerned, and I think you are pretty safe to go on that. <A> In the U.S., auxiliary power units are categorized under Powerplant for the purposes of maintenance. <A> It is a "power plant", so it would be classified as such. <S> An APU isn't much different than a small jet engine.
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The FAA Aviation Maintenance Technician Handbook - Powerplant, Volume 1 lists auxiliary power units in the category of turboshaft engines on page 1-38.
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Can an airline lay off its flight attendants and use pilots to fill the role? IcelandAir recently announced that it will be laying off its entire flight attendant staff, and plans to have pilots fill the role in the meantime. Can an airline lay off its flight attendants and replace with pilots without requiring further training or certification? Generally, pilots are trained to fly the airplane and oversee the safety of the flight - but are they qualified to act as flight attendants? Is there any area a flight attendant maybe more qualified than a pilot, excluding passenger service and a smile on the face? <Q> When I was flight crew on CRJs for a private operator we got abbreviated FA training for pilots, which was mostly a kind of crowd control course, taught by a contract FA. <S> Their training is about managing a chaotic cabin full or panicking passengers. <S> FA's are more or less under-cover riot control cops who spend their careers working as servers/attendants and are very unlikely to use their actual training. <S> So theoretically, airlines could offer flight crews FA postions, if they were willing to take the pay cut and were willing to be reminded every day where they are not, performing that undercover waiter/waitress function. <S> This is an opinion, but I would say not a difficult call; you would NOT get any takers. <S> Every pilot will take the furlough and go look for another flying job, or change careers. <S> There is just no way that someone who loves flying enough to jump through all the hoops to get into a flight deck would take that kind of "demotion" <S> (maybe... maybe... one person here or there would agree to it out of sheer desperation, but not enough to be significant). <A> Most pilots are not currently qualified to serve as flight attendants, but they could be trained easily enough following an abbreviated syllabus. <S> Since pilots are already familiar with all the aircraft emergency equipment and procedures, training would just need to focus on specific tasks in different areas of the cabin. <S> That, plus operation of beverage and food service equipment. <A> It could work both ways. <S> Having a steward that is qualified to fly or "sit in" as a flight engineer in high workload situations (take off/landing/illness to pilot or copilot/inclement weather/aircraft malfuction) would be an asset, especially on a smaller carrier. <S> Pilots could also add diversity to their job by rotating to serve passengers, if they so desired. <S> But the "people factor" is very important, some may wish to try it, others no. <S> First aid training and security, as well as diplomacy, would be talents required for stewards but would also benefit pilots. <S> All personnel on a passenger plane are vital components of a team, and some may find additional responsibilities a welcome improvement to their daily work experience. <A> At least some of the remarks here show a very poor understanding of what cabin crew are and what they do. <S> No, pilots cannot replace cabin crew without substantial formal training. <S> Cabin crew are highly trained professionals, just like pilots. <S> It's true that unlike pilots they are not in command of the machinery, and that their role requires them to do many much less glamorous, high-prestige tasks than pilots have to do. <S> That doesn't make them any less professional or trained. <S> Instead, they manage people in large numbers and their behaviour and look after their needs, in an environment that is both unnatural and stressful, and tends to provoke poor behaviour. <S> Amongst other things, they typically speak multiple languages, have first-aid skills and can deal equally effectively with a weeping widower, a gang of drunken oil-rig workers returning, someone having a panic attack, an over-entitled business executive, etc etc etc. <S> In cases of emergency, they are responsible for ensuring the safety of dozens or hundreds of frightened people, by getting them to stay calm and follow instructions. <S> Anyone who imagines that the people with these skills and training could effectively be replaced with people lacking them is dreaming.
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Yes, additional training would be required because airline flight crews don't get significant FA (crowd control) training and a pilot would have to take the FA course. It wouldn't be a difficult transition if the pilots were willing.
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Why hasn’t the Wankel rotary engine seen more use in aircraft? The Wankel rotary engine seems to have several advantages over traditional reciprocating cylinder-and-piston designs. In general, they have a much higher power-to-weight ratio, less vibration, and drastically reduced rate of catastrophic failure, among many other benefits. I can only find disadvantages related to emissions and fuel efficiency. So my question is, why hasn’t it seen more use in aviation even though it seems very well suited to this application? <Q> They do not have drastically lower rates of failure than comparable piston engines. <S> My college materials science TA owned one and had it rebuilt four times. <S> His record for the shortest distance before failure on a zero-timed Mazda rotary engine was 150 miles. <S> The breakdown mode was failure of the apex seals at the tips of the rotor due to poor lubrication, leading to excessive wear and scoring and the complete destruction of the seals. <S> According to my TA, Mazda went through more than six fundamental redesigns of the apex seal system but never could completely solve the basic problem. <A> As another answer points out, the main problem is poor reliability. <S> In a conventional piston engine, the sliding contact of the piston against the cylinder wall is mostly against relatively cool metal and is constantly lubricated by oil from underneath. <S> The contact is often maintained tightly by piston rings, which have a natural outward spring. <S> In the Wankel type the sliding contact of the rotor tip seal against the chamber outer wall is frequently against much hotter metal from recent combustion and is difficult to lubricate. <S> A separate spring mechanism is required to hold the seal closed against the firing pressure, so the whole thing is more complicated. <S> The result is that the tip seals are extremely demanding and tend to wear out or crack. <S> I seem to recall that Norton reckoned to have solved the problems but their bikes and UAVs failed to gain significant business. <S> I don't know if there were other issues affecting that. <A> I think most answers on this question are fueled by lack of knowledge on rotaries, these engines do have inherent flaws relating to apex seals but 90% of their "unreliability" claims come from pure ignorant owners (at least in the automotive world) and a complete lack of understanding on how to maintain one. <S> Most rx8's can do 100,000 kms before needing a rebuild, (average running time for that many kilometers is 2000 hours) <S> so this is relatively in line with most overhaul windows (thanks google). <S> And least us not forget the rotary engine won Le-mans in 1991 and apex sealing technology has come a long way since then. <S> However to actually answer the question the real reason is due to the effort in getting the engine certified and the costs involved. <A> Wankel RCE is still in use today for Ultralight, Parapente, and other uses. <S> Aixro, Wankel Supertec, Wankel GMBH, AIE.uk, are offering Wankel Rotary Engines for sale, research exists in India. <S> John Deere, also Curtiss-Wright, developed a line of Wankel prototypes for Aviation, in several power ranges. <S> The John Deere engine had an SFC around 240 gr/HP/hr, good enough, if you consider that it can work with low grade gasolines, heavy fuel versions of Wankel existed also. <S> A similar discussion exists in ResearchGate. <S> Light weight, compactness, faults being not that total and catastrophic as in reciprocating engines, are Wankel advantages, a 2-Stroke engine, with sudden seizing, plus torsional vibration problems in shaft from engine to propeller killed the BD-5 and some pilots. <S> The site www.rotaryeng.net by Paul Lamar, is devoted to Aircraft Conversions of Mazda rotary automobile engines, one of it holds the current world climbing speed record in its class, but if too concurrent for other engines, re-tooling costs may be dangerous to afford for many companies <S> , also, repair shops don't understand it, besides this, even if expelled from nsdap and having past some months in nazi jail, Felix Wankel had a nazi past. <S> Blessings +
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Their manifest unreliability in automotive applications is one reason they failed so badly in the marketplace.
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What would an all-flying aileron look like, and would it be a good idea? The only info I could find about someone doing this IRL was the British Army Aerorplane No. 1 , but I don't think it ever flew with them. I don't know much about how this would affect the aerodynamics, but maybe it would give more roll? I'm not that experienced in aviation, could someone tell me the implications of this? <Q> The word aileron specifically refers to a part of the airplane, usually, but not always, connected to the back edge of the wing, that is used to control roll and to turn the aircraft when used in conjunction with the rudder. <S> The British Army No. <S> 1 was based on the Wright Flyer design, and while some early airplanes did incorporate wing-warping to bend the wing itself instead of using ailerons, the No. 1 actually incorporated separate ailerons, mounted above and in front of the leading edge of the lower wing. <S> Perhaps, instead of aileron, you meant to say wing or airfoil. <S> In that case, several examples exist of modern flying-wing aircraft, such as this B-2 Spirit, which designs the entire aircraft as one large airfoil. <S> UPDATE <S> Wing-tip ailerons were utilized in some designs, such as this Stout Skycar. <S> NASA did testing on this aileron configuration to determine whether or not this design would counteract the adverse yaw effect of traditional aileron placement. <S> When ailerons are behind a wing with a large upper camber, it can partially shield the aileron that is deflected up, reducing its effectiveness. <S> Moving the ailerons to the wingtips proved to significantly mitigate this issue, although not entirely - this due to the interference between the outer edge of the wing and the inner edge of the tip aileron. <S> Nevertheless, there were also significant problems. <S> The NASA study showed a substantially reduced rate of climb compared to traditional trailing-edge aileron. <S> Additionally, there was a near doubling of drag from each wing, largely due to vortex generation caused by the necessary gap between tip aileron and wing. <S> Further, while a traditional aileron may utilize multiple hinges, a tip aileron was pivoted on a shaft, where torque loading and flex became an issue. <S> Finally, when connected via direct linkage, researchers observed that control loads felt at the yoke were often up to 3 times heavier than for conventional ailerons. <S> Here is an article by Bob Whittier explaining more. <A> Most early ailerons were all-flying surfaces fitted between the wing tips. <S> Until then most if not all other types used wing warping or nothing. <S> The hinged trailing-edge aileron made its appearance around this time on types such as the Farman and Dunne. <S> Both warping and all-flying surfaces were soon consigned to history. <S> G.T.R. Hill revived the idea in the 1920s and early 30s with his Pterodactyl series of tailless aircraft. <S> Several of these had all-flying wing tips which, like the Dunnes which had inspired him, acted as both aileron and elevator. <S> As late as the 1950s he used them on the Short SB.4 Sherpa tailless aeroisoclinic wing prototype. <S> Others such as Alexander Lippisch also tried them but offhand I cannot recall any that went into production. <S> Another variation, which has been revisited from time to time, mounts each aileron on a pair of trailing booms behind the wing tip. <S> Otto Kauba evolved a series of Skoda-Kauba designs during WWII, I cannot recall the others off hand. <S> Overall they are not a good idea. <S> Hinged ailerons are far easier to mount rigidly, so all-flying ones come with a weight penalty. <S> Moreover a hinged aileron affects much of the wing in front of it, magnifying its control effect without increasing drag. <S> Of course that means in practice that the hinged aileron can be made smaller and produce less drag. <S> But in practice maintaining pitch control is far the more important and it is generally easier to fit an all-flying tail. <A> Some radio control gliders for the slope use each wing as an aileron. <S> There are two basic types: wingerons have an elevator (so wings only need to act as ailerons), pitcherons have a fixed elevator and used the wings for both roll and pitch control. <S> For pitcherons, each wing has to move independently of the other so the wings can rotate in opposite directions for roll control, and in sync for pitch control. <S> The tranmitters have computers that take care of converting stick inputs into what is needed for roll and pitch control. <S> Example of a pitcheron model. <S> This one has a fixed v-tail (no need for rudder on slope glider) <S> The actual gliding video is dark, so you may need to turn up brightness. <S> Skip to 1:28 to see it flying: <S> Wingerons can do helicopter like spins (the image for the video is not the wingeron model). <S> I set the video begin time to the start of the video clip of the wingeron model, which shows helicopter mode at the start and end of the video clip of that model. <A> Wing warping is what you are looking for, where the entire wing twists. <S> The Wright Flyer and many early designs were wing warp designs, but they didn't persist because of the structural issues. <S> In a wing warp design structural members have to bend, which can lead to fatigue and structural failure.
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All-flying tip ailerons have the advantage of maintaining control up to and beyond the stalling point of the main wing. Examples include the 1906 Santos-Dumont 14.bis, the first plane to fly in Europe, S.F. Cody's 1908 British Army Aeroplane No.1 and the Gold Bug, modified by Glenn Curtiss from his June Bug in 1909.
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Where's the A318 on the runway that caused a 747 to go around? I screenshot 1:00 of a 480p YouTube video. The autopilot proclaims Minimums at 1:01, and the pilot flying decides to go around at 1:02 because an A318 was still on the runway, but I can't spot it, or any airplane, on the runway in the video! Can anyone? Or does anyone possess this video at a higher resolution? <Q> Look for the blinking light in the center of the runway <S> It's all you can see of it in the video. <S> I had to step frame by frame through the video to capture a frame where it was visible and another frame where it wasn't. <S> Sorry for the turbulence. <S> :) <A> The pilot already knows about the conflicting aircraft before it is visible. <S> Your question pre-supposes that the pilot flying can see the aircraft on the runway, but that may not actually be the case. <S> The PF is already aware from ATC that there is a occupation conflict and the radio is too garbled at the crucial moment to know who made the call. <S> At about 00:18 the controller warns the inbound flight: <S> Advisory, traffic is just touching down, continue for runway 09 <S> He then advises the landing traffic about the inbound flight: <S> [muffled] 307, traffic is short final, if you can't make this left turn [off the runway] expedite to the next one <S> The call goes unacknowledged and he asks the occupier to again get off the runway: [muffled] 307, expedite to the next left turn, no delay, traffic on short final <S> After the "+100" call, the controller calls the occupying aircraft again, who finally acknowledges: OK, I will make a left turn <S> By this time it's way too late for the inbound but the radio is too scrambled to tell who makes the call. <S> Either way, that's the point that the go-around is initiated. <A> Around 0:50 you can (barely) see the white strobes flashing on both sides of the centerline about 1/2 way down the runway. <S> But video like this, at night, isn't going to have much of anything visible that isn't a fairly high intensity light source. <S> Even with the pilots' vision, the A-319 unlit and a mile or more away would be hard to see; catching occluded centerline lights might be your best bet. <S> With as much background light as there is here, steady position light wouldn't be much help. <S> Strobes are a big help - and they're much more visible to the eye than they are in this video. <A> As other's have noted, there are strobe lights just about visible on the centre-line, but the go-around wasn't specifically because this crew saw the other aircraft on the runway. <S> They went around because they hadn't been cleared to land by the time they got to "minimum's" (the decision point whether to land or not). <S> At about 0:28 they were told "you're <S> traffic's just touching down, continue for runway niner" - so they've been told to continue the approach, but they don't have permission to land. <S> As soon as the other aircraft cleared the runway, the controller would have specifically said "cleared to land". <S> But they got to "minimum's" first, so without clearance to land, they have to go around.
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That's the strobe lights of the A319.
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Why can we not use full throttle in a C172 when cruising at lower altitudes? My flight training manual (FTM) says that at low altitudes we throttle back our trainers in order to not exceed recommended power settings. But why is that? Is the air close to sea level just too dense for the standard Cessna 172 engine? And at 8000 feet it's just thin enough for us to cruise at full throttle? <Q> These engines are not designed to run at maximum horsepower output all the time with a lean mixture. <S> They are designed to cruise at 50-75% of their rated max power, and deal with that level of internal heat and friction over the long term. <S> Even this is fairly hard compared to a car that runs at perhaps 20% of rated power when cruising at 60 mph. <S> Running them wide open means maximum heat, maximum wear, for not much benefit considering the power required to go faster is nearly the cube of the speed increase. <S> You must run with the mixture full rich to keep the engine cool at all, and fuel burn is a lot higher because you are dumping unburned fuel used for cooling at full power out the exhaust. <S> It's not worth it in other words, unless you are racing, so <S> the concept of cruising at not more than 3/4 of rated max power is a very old convention in piston engines, and mixture leaning shouldn't really be done above that. <S> You can run one of these engines at full throttle with a rich mixture with the RPM near red line all the time if you want, but only if you don't mind paying for the 20 thousand dollar premature overhaul from flogging the poor engine like a mule (the exhaust valves will hate you for all eternity). <S> It's pretty much the same thing as hooking up a big heavy trailer to your car, that required foot on the floor all the time just to stay at highway speed. <S> How many miles do you think that car's engine would last?(Although <S> the Lycoming being run that hard will still probably outlast the car engine in the same shoes.) <S> However, when you go up, by the time you get to 8000ft, 75% of maximum output is all that is available with wide open throttle (WOT) in the thin air, so 75% cruise, normal operation, requires WOT and no harm is done. <S> And as you go up further, you find you can't even get 50% with WOT and pretty soon you're at your service ceiling. <A> Most Cessna 172s have fixed-pitch propellers. <S> Designing a fixed-pitch prop always requires making some compromise between climb performance and cruise performance. <S> Typically this means that at low altitude in horizontal flight, at full throttle the engine would exceed redline RPM, so you have to throttle back. <S> At higher altitude the engine produces less power at a given RPM, so it isn't a problem there. <S> It's possible to use a "cruise prop" that has a coarser pitch and allows full power (or closer to full power) in low altitude cruise, but this comes at the expense of not making full redline RPM at the start of the takeoff roll, and therefore lower acceleration and longer takeoff runs. <S> Variable-pitch propellers (of which "constant-speed" propellers are a subset) avoid this dilemma, though they have their own downsides such as increased complexity and a bunch of extra weight right on the nose where you don't want it. <A> I agree with the above answers in terms of the limitations related to engine. <S> So as much as being an engine related issue, it could also be due to structural considerations of the airplane.
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However I wanted to also add that it could be possible that going full throttle at a low altitude would cause the aircraft to go out of its structural flight envelope as well.
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Can briefly explain the principle behind the inversion on this power required curve? I’ve noticed on several graphs in the “Advanced Pilot’s Flight Manual”, that power available is lower for any given speed at 10,000 feet as compared to sea level flight. The power required curves intersect at the sea level best rate-of-climb (BROC) speed. Can someone briefly explain why more power is required at 10,000 feet when below this BROC speed and less power is required at 10,000 feet when above it? <Q> Power required is drag times speed. <S> In essence, you ask why drag at the same lift and in 10,000 ft is growing either side of the best climb speed at sea level. <S> As @Kolom rightly points out, the coincidence of best climb speed at sea level being equal to lowest drag speed at 10,000 ft is just that, a coincidence. <S> There is no causal relation. <S> The power required curve is shifted right due to lower density at 10,000 ft which requires the aircraft to fly faster for the same dynamic pressure. <S> The X-axis of the plot is True Airspeed, so all polar points will shift right as altitude increases. <S> Next, you will also note a small upward shift. <S> This is caused by the lower Reynolds number at higher altitude which increases zero-lift drag at the same indicated speed. <S> The best rate of climb speed is where the local slopes of the power required and the power available curves match. <S> Then the distance between both power curves is greatest and leaves the highest specific excess power after the power required for steady flight has been subtracted from the available power. <S> If the curves would be plotted over Indicated Airspeed, they would simply shift slightly up for the power required and down for the power available as density drops with increasing altitude. <S> The author of your book chose to plot them over True Airspeed, so it might seem that the best ROC at sea level has some significance for the drag at 10,000 ft. <S> It hasn't. <S> Please make sure you read the linked answers, too, because they should help to give more background. <S> I have kept the answer short, so some things are not fully explained. <S> For example, why there is a minimum drag point at all is explained at the target of the first link . <A> I think power required curves being intersected at sea level BROC is sheer coincidence. <S> It can be a little more or a little less. <S> However I agree that it’s depicted as being an intersection. <S> My theory for difference of 10K power required curve is as follows: at lower speeds aircraft needs to be at higher AOA to produce same lift for the same airspeed at 10K, compared to sea level. <S> This higher AOA causes higher induced drag, hence higher power required. <S> For higher air speeds on the other hand, the induced drag decreases and parasitic drag becomes more prominent. <S> Therefore, power required will be less than the one at sea level. <A> There is less drag on the aircraft at 10,000 feet. <S> This means that the prop can drive the aircraft along at 120kts while moving less air than it would require at sea level. <S> The trade-off is, when the plane is flying slowly at 10,000 feet, with a lot of drag due to the high angle of attack, the prop struggles to move enough air due to the low density of air molecules at altitude.
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Because of the lower density up at 10K feet, the aircraft needs to overcome less parasitic drag.
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Will it be more efficient if airplanes flap like birds? Many airplanes have parts that are designed to mimic some features of animals. I have also read that birds are incredibly more efficient than most of the airplanes we see today. I wonder, will the future passenger airplanes resemble a big flapping bird? Considering that in the future we might have a lighter and more durable materials for wings. <Q> In short, the answer is No. <S> For many centuries, many proto-aeronautical engineers believed that the secret to manned flight would be found in complex flying machines that mimicked the flapping techniques of birds. <S> These ornithopter designs were doomed from the start. <S> Aside from the obvious issues involving strong, rigid, durable, and light materials, there are tremendously complex psycho-muscular factors involved in biological flight mechanics that are impossible to duplicate with machinery. <S> A bird has the benefit of nerve endings all over its body which provide immediate and intimate feedback of every minute shift and change. <S> Additionally, the bird has fine motor control over its flight surfaces to a much greater degree than any aircraft can realistically replicate, and all at the speed of thought. <S> The good news is, efficiency can be relative. <S> While the deft flight of a bird can be graceful, beautiful, and evolutionarily effective for its avian lifestyle, it will certainly never accomplish a trans-Pacific trip at 500 knots. <S> Mankind has learned a lot from watching our feathered neighbors, but ultimately, our journey among the clouds lies along a different path from theirs. <S> That said, some small drone applications show promising possibilities for mimicking insect wings, so mother nature may still have a few more tricks to teach us. <A> Several things come to mind: Probably not. <S> A flapping wing is only producing thrust during half its operating cycle (except hummingbirds and insects, who's wings generate thrust in both directions when hovering) <S> so there is energy wasted in the wing's recovery cycle in normal forward flight. <S> It might be better for the bird to keep its wings "fixed" and use another oscillating surface to provide the thrust, like a fish tail, but nature has apparently decided this is not a viable engineering solution for making horizontal thrust in air and in balance, it's better to oscillate the lifting surface. <S> You would not want to ride <S> is such a machine vary long. <S> The main difference between the natural world and the man-made one is the man-made one's ability to assemble separate parts and make them operate together to convert energy potential to force without touching (either elements separated by an oil film, or a rolling interface) to produce power in various forms (crankshafts, connecting rods, pistons, turbine rotors, etc). <S> Living beings must produce their thrust from elements that are physically interconnected in a single organism grown from a single egg. <S> This is a huge engineering limitation for mother nature and is why nature couldn't invent the wheel. <S> So I would say, as an engineering exercise, ornithopters are actually sub-optimal, and nature and evolution produces ornithopters because that's the only design solution available when the "design toolbox" so to speak is limited to what can be done with a single interconnected organism, and to the extent that a man made version can be replicated, nobody would want to spend more than 2 minutes in the thing anyway. <A> It is amazing how ingrained into the psyche of many aviation enthusiasts, even today, is the issue of lifting the plane "as birds" when the issue of propulsion against drag is predominant as speed increases. <S> So, reduction in drag becomes the key issue. <S> Indeed, a flapping wing is perfect for a relatively slow, lightly wing loaded bird as it "moves a lot of air a little at a time" much more efficiently than a duck holding its wings straight out and paddling franticly with its webbed feet (which would work fine in higher density water). <S> But a bird can flap its wings due to much lower wing loading, which allows to lift and thrust with the same device, and lower airspeed, which allows for a much lighter structure from relatively lower aerodynamic stresses. <S> Early biplanes with very large propellers took a similar approach until... Increasing speed placed emphasis on the need for increased thrust. <S> The higher wing loading of larger aircraft require higher speed to fly. <S> So, at the expense of efficiency and weight savings, aircraft trend towards greater but less efficient thrust, partially offset by the ability to fly higher, giving a higher True Air Speed. <S> But recently, with the incorporation of high by-pass fans (and higher fuel prices), designers are returning to the old wisdom that birds employ so well. <A> Likely no <S> but let's see <S> The relevant research study can be found here . <S> In this study, it was shown that for some insects, the induced power can be twice the ideal value in hover, and can be even higher than this in forward flight. <S> This is worse than possible with the fixed wing. <S> From the other side, the same study says that flapping wings do not show classical abrupt stall characteristics at high angles of attack. <S> This is due to the leading-edge vortex on the top surface of the flapping wing. <S> Thus, the flapping wing achieves significantly higher lift coefficient at high angles of attack and may be more effective, even if less efficient. <S> Flapping wings can provide hovering as well when fixed wing cannot. <S> Also, propeller powered insects do not exist so it is not clear how the control experiment is done. <S> If versus aircraft, the size difference may matter. <S> A 3 mm propeller or jet engine for a mosquito insect may not be a more efficient solution.
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Efficiency aside, the big show stopper is that a mechanical flapping wing machine, to the extent it can be perfected, will always suffer from the the problem of the body moving vertically in an inertial response to the wings being driven up and down.
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Why are lower VHF frequencies used for towers? So, why are usually lower VHF frequencies (around 118MHz to roughly 120MHz) used for towers and higher frequencies (around 130MHz to 136.975MHz) for ACC? What is the advantage of using lower frequencies for towers and higher for ACC since the wave propagates as a line of sight in both bands, that is, the maximum distance of the radio wave should be the same regardless if the frequency is 118MHz or 136MHz? <Q> There's no specific reason why the lower frequencies are used for towers, but it's not a coincidence that they are grouped together (mostly, there are tower frequencies that are not at the lower end.) <S> Spectrum management is a complex effort to make maximum use of the fixed amount of frequencies available for use. <S> In the US this falls under the FAA Spectrum Engineering Group AJW-1C. <S> One method of ensuring reliable safe communication is the intersite analysis. <S> Basically, frequencies have to be used by multiple ground stations based on the airspace volume that the frequency needs to cover. <S> This airspace is referred to as a frequency protected service volume (FPSV). <S> The goal is that an aircraft in the FPSV will only be able to communicate with the intended ground station. <S> A frequency that was used for both high altitude and a tower would be more difficult to de-conflict. <S> There are also other considerations that can affect the assignment of frequencies. <S> It's all spelled out in the 6050.32B - Spectrum Management Regulations and Procedures Manual . <S> It's rather lengthy at 475 pages. <S> The details of VHF/UHF Comm frequencies is in Appendix 2. <A> in that frequency range (118-137MHz) you are correct, the percentage change in frequency from the bottom to the top of the range is small, so there will be no significant change in propagation characteristics, range, data rate, etc. <S> going from 118 to 137. <S> In addition, the same radio antenna can be effectively used across the whole frequency range, simply by trimming it for resonance in the center of the band. <S> So the real question is frequency allocation <S> i.e., how it's decided who gets to operate where within a frequency band. <S> Those allocations are often arbitrary (for example, there's no reason why one end of a ham radio band would be reserved for morse code as opposed to the other end of the band) but allocating different band segments for different uses reduces the chance of miscommunication. <S> For example, if tower/unicom was blended into ATC channel assignments, then a pilot could be one channel mistuned and find him- or herself talking to the tower when they were expecting to talk to an en-route controller. <A> May not have been an explicit consideration, but the bottom of the band is pretty close to Band II FM broadcast radio. <S> 118MHz could interfere with 96.6MHz transmissions, the difference between them being 21,4 MHz, twice the usual 10.7MHz IF (intermediate frequency) <S> This is known as the "image frequency". <S> It's only problematic with a "high side" local oscillator (LO), 10.7MHz higher than the broadcast station. <S> This problem could arise with any channel up to 108 + 21.4 = 129.4 MHz. <S> You don't really want interference sources flying over millions of people if you can help it. <S> People living close to ATC transmitters may notice some interference, (which can be dealt with in other ways, e.g. choose a radio with a low side LO) but they might have more pressing noise problems. <S> So, keep the potential interferers stationary, move the mobile transmitters above 129.5 MHz. <S> (source : <S> I had a job designing a stereo FM receiver once) <S> Many years ago I used to hear LF navigation beacons (280 to 530kHz) on an AM radio, via the image frequency. <S> One played "GLG" in very slow Morse code (presumably Glasgow) - these must have been switched off about 40 years ago.
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Since towers have a relatively small FPSV, typically 5,000' high (AGL) & 15 nmi radius, the tower frequencies can be reused closer together than a high altitude sector frequency that may cover a 150 mi radius at 45000 feet.
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Why do some aircraft have multiple switches for the landing lights? A question just popped into my mind: Why does an A320 overhead panel have 2 landing lights switches? What's the logic behind that? Why isn’t there only a single switch to turn on both landing lights? <Q> On a dark morning preflight check, I can verify that the lights all work by turning each one on, one at a time, without leaving the flight deck. <S> Less lifespan on the bulbs & less disruption to the ramp to have several quick flashes of light within a few seconds, than turning everything on, walking outside to observe everything, and then going back inside. <S> Plus, it's probably a hold-over from days of minimal automation (think, <S> 727 Flight Engineer panel - now entirely replaced by automation & a few switches on the overhead panel) <S> when each {whatever} had its own switch. <S> I could get creative & invent another scenario or two when I want "this" but not "that" light on, but the preflight is probably the best example of that. <A> Some aircraft have multiple landing lights fitted to them. <S> Often larger aircraft have some of the landing and taxi lights attached to the landing gear and some landing lights are located in the aircraft structure behind transparent aerodynamic fairings. <S> This allows the crew to still make use of landing lights once the gear is retracted (the gear is usually retracted once airborne and in a continuous climb and extended at the FAF on an instrument approach). <S> Which reminds me of a “there I was...” story of mine. <S> I was flying around San Diego one overcast and cloudy night on a local IFR practicing instrument approaches into the smaller airports around KSAN (not a great idea BTW) in a Cessna 182T. <S> It was a busy night with multiple heavy arrivals into KSAN that evening and Miramar was busy with departures and launches as well as an emergency. <S> I was returning from Brown (KSDM) back to plane’s base at Montgomery (KMYF) when I got the following radio call: <S> “Cessna xxx, traffic 2 o’clock, three miles at 5000. <S> Boeing 737. <S> Report them in sight.” <S> “Cessna xxx, no joy. <S> I’m in IMC.” <S> Now you hope the controllers are professional here <S> - it is a major airport in Class B airspace - and can keep us separated. <S> And it was about that time that I saw two brilliant white beams of light piercing the clouds and passed right overhead. <S> Well, there’s the 737. <S> He was not at a safe separation and pretty damned close. <S> If he had the gear down he might have left tire tracks over the wing of my airplane. <A> Safety and redundancy (is that redundant?). <S> As a couple examples, if one of the switches breaks, you only lose that one light instead of all of them. <S> These switches do break too, they get flipped multiple times every day and are in pretty harsh environments. <S> Also, you could get a short circuit in one of the lights, or a light circuit.
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Again, having separate switches allows you to turn off only the problem light, while keeping the rest on.
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What is 'level' to a G1000? I used to fly a Cessna 550 with 'steam gage' mechanical gyros. The Attitude Indicator always had its flight director solidly on the horizon in level flight -- to the extent a mechanical instrument could be seen accurately. I recently started flying a Phenom 300 with a G1000 panel. It is curious to me that level flight in the Phenom is always about 2.0º nose up pitch: And a detailed pic of the command bars in level flight at FL430: My question: Why would level flight be indicated by nose up pitch? What does 'level' actually refer to? <Q> Level flight just means not climbing or descending. <S> Where the nose is actually pointing is another matter. <S> The pitch you are seeing is the "deck angle". <S> Pitch attitude is normally referenced to the longitudinal axis of the fuselage (and normally, the cabin floor or deck) relative to the horizon for the loading and speed you are at. <S> The deck angle will be the overall AOA of the wing for a given flight condition plus or minus the wing incidence relative to the fuselage. <S> If the incidence is zero, meaning the wing mean chord line is parallel to the fuselage's long axis, and the wing is operating at a 2 degree overall AOA at that altitude and speed, there's your pitch attitude; <S> +2. <S> I would expect to see at least a deck angle of a couple degrees when flying at 210 kt indicated in a jet, unless the wing had an incidence of several degrees. <S> Say the Phenom has a wing incidence of about 1 degree, and that the wing is actually working at an overall AOA of 3 degrees at 210kt; the resulting deck angle would also be +2. <S> In the Citation with the mechanical spherical attitude indicator with Flight Director, you have to allow for the parallax error due to the gap between the indicator and sphere if your sight line is off a bit, and perhaps the Citation II has a higher wing incidence, and along with a lower wing loading cruises with a lower deck angle of 1 degree or less. <S> With a mechanical indicator it'd probably look close enough to 0 degrees to make that conclusion. <A> At FL430 cruise, your aircraft is probably exhibiting a real nose-up pitch attitude in order to achieve the wing's best-economy AoA at that point in the flight envelope and the electronic detectors in the pitch attitude indication system are showing you this. <S> Taking a vacuum-driven "steam gauge" gyro apart reveals a set of clever doodads called erector mechanisms inside it which are intended to determine the average direction of " up " on long-term (~tens of minutes) timescales. <S> It is possible, then, that the steam gauge system was nulling out the persistent (but slight) steady-state nose-up pitch condition in high altitude cruise. <A> In level flight, it's natural to have some nose-up pitch. <S> You need some angle of attack to produce lift that counteracts gravity. <A> I was always told that an analog AI should be set to the white horizon line while on level ground, rather than for straight and level flight. <S> The reason for this is that it offers a truer picture of the pitch of the nose above the imaginary horizontal plane. <S> For example, a Cessna 172 in straight and level flight will actually be in an orientation with the nose about 2.5 degrees above horizontal. <S> It’s entirely likely that the Phenom balances S&L with a slightly nose-up pitch as well. <S> Unfortunately, the G1000 does not offer the ability to calibrate this for yourself according to preference. <S> Perhaps, take solace in the fact that you now have a somewhat more accurate reading of the actual pitch of the aircraft during its various maneuvers and configurations.
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"Level" on the attitude indicator probably refers to 0 angle of attack, or how the plane sits when it's on the ground wheels down and the G1000 is being calibrated.
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Why does aileron response diminish as speed becomes slower, from slow-flight up to the stall? (In a light trainer) Can someone phrase the explanation to this in simple words as you would explain to a student? <Q> This is real easy, no explanation required: <S> Tell your student to stick their hand out the window of the car driving 25mph in the city and rotate it like an aileron. <S> Then have them do it on the freeway doing 60mph. <S> Feel the difference? <S> Did smaller movements produce larger effects at higher speeds? <S> Practical examples are typically more effective at driving a point home than a lot of words. <A> Very simply, because the dynamic pressure drops as you slow down, making all aerodynamic controls more sluggish. <S> Aileron works by locally increasing the lift of one outboard wing and decreasing the lift of the other, thereby creating a torque or rolling moment. <S> For simplicity, let's think that for every degree of aileron deflection, there is an associated increase and decrease in the local lift coefficient for TE down aileron and TE up aileron, respectively 1 . <S> You may remember that the total lift differential is proportional to the lift coefficient, but also to the dynamic pressure. <S> You may also remember that dynamic pressure is proportional to the square of the true airspeed. <S> Therefore, as you slow down, even though the lift coefficient differential remains more or less constant for the same aileron action, the total lift differential decreases as a square of the speed, and the same for the rolling moment. <S> 1 <S> The change in local lift coefficient is not constant across flight regime. <S> As the AOA increases toward stall, significant nonlinear effect arises. <A> To make the answer as simple as possible, an aerofoil will increase lift in two ways, either by going faster or increasing the angle of attack. <S> When the aileron moves up or down it’s changing the shape of the wing and either increasing or decreasing the angle of attack. <S> So, if you fly fast just a small aileron deflection will produce the necessary lift to raise the wing. <S> Conversely, if the aerofoil is going slow the aileron will require a greater deflection to create a larger angle of attack for the same amount of wing movement. <S> Hence at high speeds the aircraft will feel very responsive and at low speeds will feel unresponsive particularly as it approaches stall speeds. <S> You should understand this is a very simple overview and there are many other aspects to consider. <A> The lift that is generated by an aileron at a fixed deflection (e.g. 5 degrees down) is proportional to the volume of air that is deflected downward per unit of time (e.g. per second). <A> In the flight envelope you describe, the aileron response is affected by two factors: <S> the change in lift from the movement is related to thespeed of flight. <S> As the speed reduces, the force diminishes, and, when the wing stalls, airflow over the aileron is substantiallyturbulent and no usable effect results from aileron movement. <S> This applies equally to other aircraft, not just light trainers. <S> However, sophisticated fly-by-wire controls are often designed to not allow stalling and prevent the effect from being noticed under normal flight conditions. <A> why does aileron response decrease ... from slow flight up to stall. <S> Yes, controls definitely get more sluggish slowing down from cruise speed to slow flight, due to the reduction of aerodynamic force on their area. <S> From slow flight to stall, with ailerons, one must be aware of additional effects beyond reduction in airspeed. <S> Ailerons work by moving one up and one down. <S> All well and good until one goes to higher angles of attack. <S> There is a loss of effectiveness for the upturned aileron due to flow separation approaching stall. <S> This is compensated by increased angle of attack of the downtrend aileron, but it will stall first. <S> This is the dreaded "aileron reversal" that can lead to a spin. <S> Note that in the PARE spin recovery method, ailerons are nuetral. <S> From slow flight to stall, use your rudder and turn coordinated to stay safe. <A> Easy - it's no different than the WHOLE WING exhibiting diminished response at low speeds! <S> When you pull back on the yoke, that IS because you are getting diminished response from the wing. <S> The ailerons likewise require more displacement for the same effect at low speeds compared to high speeds. <S> If the student then can't grasp why the whole wing doesn't work at slow speeds, then you at least have uncovered the level of the student's intuition and understanding!
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As speed is reduced the volume of air being deflected downward per unit time is reduced so the lift created by the aileron is also reduced and the aileron become less effective.
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What is airflow direction in turn? Let imagine that we put wind indicator on rotating merry-go-around.Will wind indicator stay prepedicular to the radius of circle,showing tangetinal airflow velocity? (Wind indicator has equal mass and distance from pivot point so moment about pivot point is zero.It desing like this to stop centrifugal force to move one end out of turn..) I think wind indicator will be prependicular to radius of rotation..(I ask this because of glider yaw string...) <Q> Let imagine that we put wind indicator on rotating merry-go-around. <S> Will wind indicator stay perpendicular to the radius of circle,showingtangential airflow velocity? <S> A very lightweight piece of yarn would do essentially the same thing, though there would be a very slight tendency for the apparent "centrifugal force" to displace the free end of the yarn toward the outside of the circle. <S> However the problem gets more tricky if the length of the wind indicator is not trivially small compared to the radius of the circle. <S> If the length of the wind indicator is not trivial, this means that the "vane" or fin is located well aft of the weathervane's pivot point. <S> The relative wind at every point along the circumference of the circle is aligned with the line that is tangent to the circle at that point . <S> So when the vane streamlines itself to to the relative wind which is tangent to the circle at a point <S> well behind the pivot point of the weathervane, this means that the weathervane is not parallel to a line drawn tangent to the circle at the pivot point of the weathervane. <S> Rather, the weathervane is skewed with its nose outboard, and its tail inboard, of the line drawn tangent to the circle at the pivot point of the weathervane. <S> Your intuition is correct that this is why tend to see some sideslip in circling flight, especially in slow-flying aircraft whose linear dimensions are not trivial compared to the radius of turn. <S> The vertical fin tends to streamline itself to the relative wind, which means that the fuselage tends to be parallel to a line drawn tangent to the circular flight path at a point <S> well aft of the CG . <S> This effect is illustrated in section 8.10 of the "See How It Flies" website . <S> In short, in turning flight, the "relative wind" is curved, rather than linear. <S> It curves to follow the curvature of the flight path. <A> If the vertical surface at the nose and at the tail of the wind indicator (usually called a weather vane) are both flat plates, have the same surface area and are equi-distant from the pivot point <S> then the wind indicator will remain perpendicular to the radius because the force generated by the nose and tail will be equal. <S> If, however, it is designed like a normal weather vane and has a larger surface area at the tail then the nose will point slightly away from the merry-go-round, in your diagram above it would rotate slightly clockwise. <A> If there is no moment around the pivot point, then you do not have a wind indicator at all. <S> One prominent writer here spoke of "curved airflow" in a turn, and this is a good example of it. <S> In order to be a "wind indicator" one must have greater Area aft of the pivot point. <S> Because it is fixed, mass distribution is not a factor in indication of airflow direction, but may affect rapidity of response to changing relative wind. <S> The solution to understanding is to exaggerate the point of contact between the circle and the pivot. <S> One will see that the back end has air flow from the outside and the front end from the inside . <S> Because the back end has more area , the front end will point out of the circle. <S> It really depends how large a circle you are working with. <S> For an aircraft with a turn radius of 1000 meters, the "weather vane" works fine. <S> But now comes an interesting twist. <S> Because the weathervane is accelerating in a circular motion, center of mass <S> must be at the pivot point , or error with be introduced to the direction of "point". <S> Interestingly, for a known radius and rpm, placing the CG slightly behind of the pivot point will make the arrow point tangent to the circle! <S> Circular physics can be a bit different.
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Assuming that the indicator has a mass distribution such that the apparent "centrifugal force" from the rotation has no effect on it, and also assuming that the physical length of the wind indicator is trivially small compared to the radius of the circle , then yes, the wind indicator will remain perpendicular to the radius of the circle at the point where it is located, showing that the "relative wind" is tangent to the circle.
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What determines the maximum ground speed of hot air balloons? I am wondering how the ground speed of hot air balloons is controlled. The wind is obviously going to have a large influence upon the ground speed, but apart from wind effects, do hot air balloons have the ability to control their ground speed? If so, how? Is there a maximum limit to the ground speed of a hot air balloon? What factors contribute to this speed limit? <Q> do hot air balloons have the ability to control their ground speed? <S> If so, how? <S> This was a burning question in the nineteenth century and many attempts were made to influence ground speed, apart from rising into higher altitudes and testing whether the wind direction there is different. <S> Naive people added sails but had to notice that those remained limp and only added weight. <S> Others added paddles or engines ( steam , electric and gasoline engines were tried) but success was limited before Zeppelins started to make directed lighter-than-air travel routine. <S> An interesting variety was tried by the Swedish balloonist Salomon August Andrée who added three long ropes to his balloon, their ends dragging on the ground. <S> This caused drag which slowed the balloon, thus giving it some speed difference versus the wind. <S> Now, with some relative wind, sails could indeed generate a force which could move the balloon sideways. <S> However, when tried in 1897, two of the ropes were lost during launch and the remaining one proved ineffective. <S> Andrèe's balloon (picture source ) <S> Is there a maximum limit to the ground speed of a hot air balloon? <S> No, if the balloon rises into the jet stream, it can travel at several hundred miles per hour. <S> There is no speed limit once the balloon is up in the air. <S> However, filling and launching the balloon requires calm winds; hot air balloons almost never start in winds higher than 10 miler per hour. <S> Landing in higher winds becomes dangerous, so here also a calm wind is preferred. <S> What factors contribute to this speed limit? <S> This is not about ground speed limits, but wind speed limits: <S> While there is no fixed limit, higher winds will prevent the envelope to stretch out completely and rise up when being prepared for launch. <S> Instead, the windward side will remain dented. <S> During landing, the gondola will be dragged along on the ground when wind is too high. <S> Both these factors let balloonists prefer calmer wind for take-off and landing. <S> Once the balloon is up in the air, no such limit exists any more. <A> A hot air balloon has no means of (horizontal) propulsion. <S> As such, it will not move relative to the surrounding medium (the air). <S> If the air moves relative to the ground (wind), the balloon will remain stationary relative to the air, and thus also move over the ground. <S> In other words, if the wind is blowing at 10 knots, the balloon will have a ground speed of 10 knots. <S> If the wind is blowing at 200 knots, the balloon will have a ground speed of 200 knots. <S> Regardless, from the perspective of the balloon, it will be stationary (relative to the air). <A> The only horizontal forces which act on hot air ballons are that of drag because of wind. <S> In other words, balloons are pushed around only by wind. <S> There is no other horizontal force (e.g. motor, or other means of propulsion) which act upon the balloon. <S> This means that as soon as the balloon reaches the wind velocity, it will not feel any other horizontal force. <S> If it slows down/speeds up for some reason, the wind will push it again until it reaches the wind speed. <S> Therefore: The ground speed of the balloon is always that of the wind. <S> As a side note: Balloons exploit the fact that at different altitudes the wind blows in different directions and at different strengths. <S> By flying at different altitudes, the ballon can use the different directions of the wind to reach its destination. <A> An ordinary hot-air balloon drifts with the wind and <S> so its ground speed is always that of the wind. <S> Some control over flight direction is possible by knowing or guessing the wind direction at different altitudes and climbing or descending to a level where the wind is favourable. <S> A hot-air "dirigible balloon" or airship has an engine and propeller. <S> But they have been few and far between <S> , I don't know if any are still flying.
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Balloons travel with the wind, so all their motion over ground comes from air movements.
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Why is fuel quantity expressed in flight hours Going through a few aircraft documentaries online, I've noticed the thing that they usually express the fuel quantity in flight hours. Ex - A 747 burns 4 litres of fuel every second. So with a ton of fuel, it'll stay in air for roughly 3-4 minutes. Why are flight hours a necessary term while consider fuel quantity? I mean shouldn't they be worried about how much distance they can cover in an emergency to reach an airport, instead of how long they can stay in the air?Seems a question related to endurance but couldn't find any proper explanation <Q> It’s primarily due to wind. <S> Aircraft move through the air at a certain speed, which makes it tempting to give range in miles (or kilometers), but the air itself is moving as well, and often at a large enough fraction of the aircraft’s airspeed that it materially affects range across the ground. <S> For instance, say you have a Cessna 172 with four hours of fuel (plus reserves) and a cruise speed of 110kt. <S> With a 30kt tailwind (140kt ground speed), your range is 560nm. <S> But going the opposite direction with a 30kt headwind (80kt ground speed), your range is only 320nm—just over half as far! <S> To make it even more complicated, the winds will have different directions and speeds at different altitudes and locations, and all of that changes over time too, which is one of the reasons pilots (or dispatchers) have to carefully plan each flight’s route and fuel load, even for a “fixed” daily route between the same two airports. <A> In other vehicles, like automobiles, measuring fuel quantity in miles (or kilometers) makes more sense because there is usually a fairly direct correlation between fuel burn and mileage. <S> This is not the case with aircraft. <S> The distance that a plane can travel on a single tank of gas will vary widely, based on atmospheric conditions. <S> Headwinds may not affect cars very much, but a 40 knot headwind can just about cut a small plane's cruise speed by half. <S> Prop planes don't work as efficiently at high altitudes, jets don't work very efficiently at low altitudes. <S> It just makes more sense for a pilot to know how long the engines will keep running - then they can calculate the available distance based on the current conditions. <A> The unit of measure used for fuel is entirely dependent on the context: <S> When discussing endurance or talking to ATC you refer to fuel in flight time. <S> When calculating weight and balance you refer to it by weight (kilograms or pounds). <S> When computing cost or talking about tank capacity you refer to it by volume (liters or gallons). <A> It is the most practical method for an aircraft with which communication has been lost.
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As far as air traffic control is concerned, fuel endurance is the measure which air traffic control uses to initiate search and rescue if the aircraft becomes overdue.
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What kind of assistance can another aircraft provide to an incapacitated pilot? A recent incident unfolded as follows: An aircraft overflew the planned destination and did not respond to radio calls on any frequency. ATC decided the pilot might be incapacitated and asked another pilot whether he could get close to that aircraft to take a look. The other pilot did that and observed no reaction to signals such as rocking the wings or extending the landing gear, however the incapacitated pilot was changing the course slightly to maintain separation. Eventually the pilot resumed radio contact (speaking in a slurred voice) and upon insistence from ATC landed at the closest airport without further incident. All this time ATC was asking the other pilot whether they would still stay in the area, which they did until the landing. There’s a VASAviation video with the entire radio conversation. How can the other aircraft help beyond what they already did? Why did ATC want them around after getting in touch with the incapacitated pilot? Despite the aircraft belonging to the Royal Flying Doctor Service of Australia, it’s not like they could provide medical help. What else could have happened after radio contact was restored that would have necessitated some kind of action from the other pilot? <Q> For example, if the second pilot had observed that the 'incapacitated' pilot was actually awake and alert and there was a second person in the cockpit brandishing a gun, I think it's safe to assume that the response from ATC, law enforcement and the military would have been different. <S> The worst case is that the incapacitated pilot never recovered and simply crashed. <S> In that case the second pilot could give ATC a precise location for rescuers, which could be important in a more remote area. <S> Especially if ATC had no radar coverage. <S> The incapacitated pilot could have recovered but still been disorientated and unable to communicate properly. <S> It's possible that the second pilot could have led them to a nearby airfield. <S> That would still require some understanding and communication between them, and the second pilot might not have been comfortable with doing it, but it's an option. <S> It's possible that the incapacitated pilot recovered but couldn't talk directly with ATC. <S> That could be because they drifted down to an altitude below ATC's radio coverage, or couldn't change frequencies, or whatever. <S> The second pilot could relay calls from ATC in that case, assuming that they could work out which frequency the incapacitated pilot was on. <S> Relaying calls from ATC to another aircraft is fairly common. <S> I'm sure we could all come up with other ideas, but I think the first point is the most important <S> : when something strange is happening then it's best to gather as much information as possible. <A> In the particular incident you are referencing, the incapacitated pilot was delirious with hypoxia. <S> After the spotter confirmed that the pilot was conscious and non-evasive, ATC asked the spotter to remain nearby and try to get the pilot's attention visually while chanting "oxygen oxygen oxygen" over the radio. <S> They understood that in his compromised state, he was more likely to get the message if he could see AND hear something to snap him out of his stupor. <S> Beyond certain specific actions, (like in this case) there is not much that another aircraft can do to help with medical issues, beyond providing moral support. <S> Sometimes, though, that may be just enough. <A> ATC may have wanted the other plane to keep an eye on them in case they crashed, which could save hours or days of someone else trying to find it again. <S> Such a delay could make a life-or-death difference to someone who survived the initial crash but with serious injuries. <A> There was an interesting example of this in the UK perhaps ten years ago. <S> The solo pilot of a small plane lost his sight while in the air, an RAF instructor went up in a Tucano from Linton-on-Ouse and (eventually) guided him to a safe landing. <S> I'm afraid I have no information on whether the pilot flew again. <S> This is obviously very similar to the example recounted by @Tonny, which suggests that it might be a comparatively common scenario; and they're clear examples of a pilot on the scene being able to assist rather than just report. <S> Later: found this from November 2008 http://news.bbc.co.uk/1/hi/england/north_yorkshire/7715345.stm <S> Reports elsewhere suggest that the pilot regained at least part of his eyesight. <S> Also https://forums.flyer.co.uk/viewtopic.php?p=737791 although I can't get the link to the talkdown recording to work.
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This is speculative and I haven't looked at the links you gave, but I can think of a few things: Having another aircraft there gives ATC a way to gather information that they otherwise couldn't.
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What is the impact of camber on CLmax? I was reading Aerodynamics for Engineering Students by Houghton and saw the following graph: A lot of other sources say that increasing camber increases CLmax, like the graph below. I am a little confused by what camber actually does to CLmax? An explanation which focuses on the physics would be very helpful! <Q> Camber directly affects the amount of circulation an airfoil can generate, adding camber will always generate a higher zero alpha lift coefficient (intersection of the lift coefficient curve with the x=0 axis) up until a point that there is too much camber to sustain attachment. <S> This leads directly to the question asked - does camber increase CL_max? <S> For any given AOA, there is an ideal suction side geometry that generates a pressure distribution that is always on the edge of separating. <S> Liebeck defined this ideal shape but only for laminar flow, for which the boundary layer equations are closed form, this was all based on the work of Stratford who came up with the ideal pressure recovery. <S> Having a surface that is about to seperate everywhere can even be true for a symmetrical section at some inclination, although it's not going to look like a NACA 0012/15 or anything familiar. <S> The effect of the pressure surface on the amount of circulation generated, is much more insignificant than the suction surface, but it is not zero. <S> Therefore, a cambered airfoil will make slightly more load at max CL than a symmetric section. <S> In reality, there is no magic button to increase, decrease camber. <S> Airfoils are complex geometries that cannot be driven by one parameter without affecting everything else. <S> Unfortunately there is no easy +camber <S> = <S> +max lift coefficient relationship, but for a cambered and non-cambered airfoil designed to operate on that separation limit, the cambered airfoil will generate slightly higher max lift. <A> In general, boundary layer development is key to understanding the role of airfoil geometry on performance metrics such as CLmax. <S> In this case, with increasing AoA, positive camber creates a reduced adverse pressure gradient near the leading edge thus delaying the onset of massive boundary layer separation at stall angles relative to a symmetric airfoil. <S> So, with positive camber, CLmax could be higher since massive flow separation occurs at a higher AoA. <S> Of course, you could use camber to reduce CLmax relative to symmetric airfoils. <A> Camber is measured by taking the midpoint between the top and bottom of the wing and comparing it to the chord line, which runs from the leading edge to the trailing edge. <S> The top graph simply shows that bending the leading edge down, as slats do, will begin to generate lift even if the wing is at zero AOA, because the top of the wing now has a greatercurvature than the bottom. <S> Notice <S> a symmetrical wing (no camber) at zero AOA will have its upper and lower "lift" cancel out, and must be at a positive AOA to generate lift. <S> The undercambered wing in the second graph will produce a greater Coefficient of Lift because of it's ability to "trap" more air underneath the wing and force it downwards. <S> But one should be aware of the drag penalties of this type of wing, requiring much more thrust generate the same amount of lift as the symmetrical airfoil moving faster. <S> This is why cambering (with slats and flaps) is generally not utilized in cruise.
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Adding camber by 'bending' the airfoil somewhere near the front of the chord will give some more circulation, but also probably increase the departure angle, and create a risk of separation towards the trailing edge where the pressure recovery is too steep for the boundary layer to cope with.
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Are there two types of runway holding position sign? I came across this section on runway holding position marking while reading Jeppesen Airway Manual, which got me very confused. My question is: Is Pattern B describing another type of runway holding position sign other than the one described in Pattern A? Or is it just describing the ILS critical area boundary marking for CAT II & III approaches? I'm asking this question because I've never heard in my whole aviation career that there are "two" runway holding position markings, nor seen one. <Q> I’ve never seen the critical area hold bars referred to as a type of runway hold bars, but they serve the same general purpose when the critical area needs to be protected , so I can understand the point of describing them together. <A> The "pattern B" markings designate the boundary of the ILS critical area, from which aircraft (and other things) are excluded during ILS operations . <S> An aircraft exiting the runway knows it is safely outside the ILS critical area by passing that boundary marking. <A> The Jeppesen description is confusing (to me) but have a look at the AIM 2-3-5 and specifically Figure 2-3-16: <S> It looks like the pattern
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A image you posted shows runway holding position markings only; pattern B shows runway holding position markings and ILS holding position markings.
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What's this black rectangle painted on the side of a V-1 flying bomb? A friend sent me a photo of the V-1 flying bomb on display at the Air Zoo in Kalamazoo. What's the black painted rectangle on the side of the fuselage? The writing isn't much help... Nicht auftreten is the German equivalent of "No step," but I don't know what Abstellpallung means, except that abstellen is "to cut off / shut down." I can't find Pallung in any German dictionary. The label appears to be pointing to the black rectangle, which appears to just be painted on. I also can't find this rectangle in online V-1 photos. <Q> A "Pallung" is a piece of wood (or something similar) that prevents ships (or something similar) from falling over when they are on land. " <S> abstellen" means to put something down (such as luggage) or into storage. <S> There are some recent articles that contain the word "Pallung" on google news, such as this one . <S> Assuming that the book depicted in this pdf is authentic, you can see what an Abstellpallung for a V1 looks like on page 29, indicated by the letters b and c: <S> Note that the text twice says "Markierung am Rumpf beachten!" <S> (mind the markings on the fuselage), which probably corresponds to the black rectangles mentioned by the OP. <S> (Some native German users have indicated that they have never heard the word. <S> Neither have I, until today. <S> I am not sure about other languages, but in German, some domains have very specific vocabulary that a layman will almost never get in contact with. <S> One example of this is anything connected with ships, another one is hunting, and there are probably some more. <S> The manual contains another example just in the preceding sections (what does "heißen" mean here?). <S> So "I have never heard the word <S> " may just mean that someone is not familiar with some particular domain.) <A> abstellen is "to cut off / shut down." <S> I don't know what Abstellpallung means. <S> Me <S> neither. <S> It seems to be a quite rare nautical term, meaning "strutting", "bracing" or "propping" 1 . <S> A " Palle " is a (wooden) support block on which ships would rest in a dry dock. <S> The closest match I found in an actual dictionary is the adjective "pall" from the Low German language [1] [2] which means "steif" or "fest" (stiff/firm) in German, and certainly could also be used as a verb ("make firm", to strut). <S> Even the Duden knows the noun " Pall " from the same word origin, as nautical term for a pawl (ratchet) that fastens a capstan. <S> What's the black painted rectangle on the side of the fuselage? <S> It appears to be the point where the fuselage is meant to rest on a support frame for storage. <S> I would guess that location is reinforced by the internal structure 2 , like @PeterKämpf said, for jacking it up. <S> 1: <S> Not sure what the subtle differences between these terms are, I'm not a native English speaker. <S> 2: Or not . <A> Contrary to some other answers <S> Palle is actually a real German word, though it is used mostly in context of shipyards. <S> A Palle is a wooden or concrete block on which ships are resting in drydock. <S> See also this German Wikipedia entry: <S> https://de.wikipedia.org/wiki/Palle A 'Abstellpallung' thus means a location one the V-1 where one can safely support it on a Palle for storage or maintenance. <S> The black rectangle marks that location. <A> "Abstellpallung" isn't a word in German. <S> If you search the web for this word, you will find lots of links to the V-1, and it seems this word has been exclusively used on restored V-1 in several museums. <S> But nowhere else. <S> The conclusion is clear: This is the result of a poor restoration and everyone seems to have copied this from its original source. <S> Which was not a V-1, but some ignorant restorer. <S> Edit: <S> I stand corrected. <S> While extremely unusual, Palle or Pallung seems to be used for wooden blocks on which a ship rests. <S> But outside of restored V-1s in museums it is not used in the context of German WW II aircraft, as fas as I know. <S> I'd be interested to see evidence to the contrary, though. <S> You will also see that the original word at this location is "Hier aufbocken Auf Abstellbock" which is proper German (except for the capital A in Auf) and means "Jack up here on parking trestle". <S> But even the vey unusual "Abstellpallung" will be found, but at a much more forward location. <S> V-1 in the Imperial War Museum, Duxford (picture source ) <A> Abstellpallung means storage pallet in English, there is a similar marking on the right side opposite that one in the picture as well as left and right rear. <S> These are likely the places where the storage/transport pallet was supposed to contact the weapon structure. <A> You can just make out the writing (unreadable) and downward pointing arrow on this photograph. <S> Source <S> https://www.historyanswers.co.uk/wp-content/uploads/2014/11/Credi-Bundesarchiv-Bild-146-1973-029A-24A-Lysiak-CC-BY-SA.jpg <S> This second photo shows the other side (different personnel so not a mirror image). <S> This supports the idea of it indicating a a pair of strong points for storage. <S> In the second photo, you can see what appears to be pale-coloured writing on the section just after the nose cone. <S> Maybe an image processing expert could help. <S> I'll try asking on a suitable stack exchange! <S> Finally - this photo shows what is claimed to be a 1944 photo of a much cruder-looking missile. <S> If there is any writing in that area, it appears to be hand-painted.
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That's one meaning of the word, what we need here is "putting down", "parking" or "putting in storage". I can't find Pallung in any German dictionary.
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Why did wings start to be made with aluminium skin instead of fabric? Why did engineers start designing planes with aluminium skin on the wings instead of fabric covering? While the force of lift acts on the skin, to my knowledge it is not subject to high stresses <Q> Wings and fuselages are subjected to twisting loads as well as bending <S> so they need to be torsionally stiff. <S> Prior to aluminum, the options were to make the wing/fuse with a frame of spars and ribs with fabric to provide the aerodynamic contours, braced with struts and/or wires to provide the torsional stiffness as well as resistance to bending, or, to do away with the struts and brace wires and make a monocoque structure (like an eggshell) with a plywood skin to provide torsional stiffness (with the spar beam inside for bending). <S> If you wanted to go fast, you had to do away with all the bracing so <S> plywood monocoque was the way to go. <S> When "duraluminum" came along after WW1, it was realized that as well as replacing sitka spruce for spar beams and ribs, it could also replace plywood for a stressed skin monocoque structure. <S> You could build an airplane in the 1930s using plywood stressed skins bonded to wood ribs and spars, or aluminum stressed skins over aluminum spar beams, and have pretty much the same performance. <S> You could make your egg about of plywood, or aluminum sheet, and it was pretty much the same egg. <S> , it was a no brainer to switch, once the metallurgy started to become understood well enough to use it as an engineering material, and plywood skinned wooden airplanes faded quickly. <A> Aeroelastic flutter is an issue at higher speeds and the simplest way to overcome that is to use stiffer materials. <A> I would assert that the breakthrough occurred when aluminum became (relatively) inexpensive to extract from ore on industrial scales. <S> There was also a psychological factor, in that the popular american football coach Knute Rockne died in the crash of a Fokker passenger plane with a wooden wing when it came apart in a storm. <S> All-metal construction then became a selling point for airlines. <A> Principally to carry greater loads. <S> The skin on the wing forms an integral part of the wing box, which provides greater structural rigidity. <S> It also provides better aerodynamic characteristics under loads. <S> For instance Boeing has a particular way that it designs its wing scans, which is a proprietary secret, that causes them to flex when under load for better aerodynamic qualities.
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There were so many manufacturing and durability advantages to aluminum (no glue, no wood rot etc etc)
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First time passenger flight by two pilots? In this video , the captain proclaims after take-off: We were nervous about this, but takeoff went smoothly It was his first passenger flight in the A350, but still... not exactly what I would want to hear as a passenger. This got me thinking, does it ever happen that two pilots take their first passenger flight on a given type together, or will it always be the case that if it's someones first time, the other pilot will have X amount of hours on that type? <Q> It is never “the first time”. <S> What he is really saying is that after many hours of flying the aircraft (or an approved simulator) this is the first time doing a revenue flight with passengers. <S> Previous flights would have been training flights. <S> When a new aircraft type is first introduced to an airline, it can be expected that the entire crew is doing their first revenue flight after training. <S> What is not expected is that the pilots announce it to the passengers. <S> I would not advise doing that because the passengers might not understand, and it would put doubts in their minds, as it did for you. <A> Just to point out the obvious: <S> This got me thinking, does it ever happen that two pilots take their first passenger flight on a given type together <S> You don't even have to know anything about aviation to be able to answer this question. <S> You can answer this question with common sense and basic logic: <S> If it's a new aircraft type, then by definition, nobody will ever have flown this particular aircraft type, which means that there must be at least one flight where all of the crew are taking their first flight. <S> It is simply not possible otherwise. <S> Of course, all of them will have had simulator training on that aircraft type, and all of them will have training flights and checkout flights on that aircraft type, but just by the laws of basic logic, it is impossible for there not to be a flight where the whole crew has never flown a revenue flight with passengers before, simply because there always must be a first flight. <A> [D]oes it ever happen that two pilots take their first passenger flight on a given type together [...]? <S> Yes, it does. <S> In fact, it happened in exactly that flight you linked: <S> Found out that it was the first passenger flight for all of us pilots , but everything went perfect thanks to Scandinavian cooperation and teamwork. <S> ( YouTube video description, emphasis mine) <S> There is no legal requirement to have any actual experience with passengers on that type. <S> As long as all the pilots have successfully completed the type rating, which includes flight time in the actual aircraft or a level D simulator, and at least the PIC (pilot in command) has the full ATPL (Airline Transport Pilot Licence), which requires at least 1500 hours of flight experience (at least in Europe, not sure about US), there is nothing wrong with that. <S> Note that based on the other videos in that YouTube channel, the pilot seems to be type rated on the Airbus A330 as well, which is a very similar aircraft. <S> An earlier video Learning To Fly The SAS A350 <S> In Toulouse shows the transition training from the A330: <S> The one and only simulator session on the transition course from the A330 to the A350. <S> It’s awesome plane. <A> My answer considers EASA (European) rules. <S> As a general rule after a transition training in simulator, there is line-flight training in real aircraft. <S> That is flying with (experienced) instructor, although there are passengers onboard. <S> The length of this line-flight training depends on previous experience of the trainee, but it cannot be omitted. <S> After line-flight training there is line check (usually again on actual normal commercial flight) after which the trainee can commence operations without instructor pilot onboard. <S> In Europe, there is a concept of "in-experienced" crew member. <S> After line-flight training and successfully passed line check, the pilot is considered in-experienced for at least 100 flight hours and 10 sectors. <S> The key idea here is that two crew in-experienced crew members cannot fly together. <S> So, before two pilots are allowed to operate together, both shall have at least around 120-150 hours of flying the type under their belts. <S> There are some deviations on this, and most notably airlines can temporarily ignore the in-experienced status when introducing new aircraft types into their fleet. <S> But what they cannot do is skip mandatory line-flight training. <S> It is not uncommon for airlines to buy training for their instructors from other airlines which already operate the type or have instructors from other airlines flying with their newly acquired planes with company pilots. <S> The case of A350 is little bit different, as it is considered as a "same type" as A330 and they have common type rating endorsement. <S> Many of new A350 pilots are already A330 pilots they can skip some of the line-flight training involved. <S> There is some sim training in between. <S> With my operator I had couple of flights with instructor when transitioning from A330 to A350. <S> There was no separate line-check or in-experienced status, as I already was active with A330. <S> So I guess in theory it might be that two A330 pilots can fly A350 together after transition course in simulator. <S> Partial source: https://www.easa.europa.eu/sites/default/files/dfu/Consolidated%20unofficial%20AMC%26GM_Annex%20III%20Part-ORO_0.pdf <A> However, that is a very rare case. <S> In general, a new pilot (either to that type or to the airline as a whole) will only be paired with certain more experienced pilots until their training is deemed complete, so you would never have two green pilots on the same plane.
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For the very first flight of a new type at a given airline, obviously none of the pilots will have flown it with passengers before, though that crew will have undergone extensive training in sims and empty planes.
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Why don't piston engines require as heat resistant materials as jet engines? Piston engines often get away with using aluminium as their heat exposed material, while even the early jets required inconel to operate. Is that because the combustion takes only, for example, half of the time for two stroke engines hence half the temperature? Still compression ratio of a typical two stroke is twice higher than early jets, while the melting point of aluminium is more than twice lower so it doesn't add up, as if there was another reason for their higher heat durability <Q> Lubrication. <S> The low wear of piston engines is due to an oil film between piston rings and liner, so both never get into immediate contact. <S> This perfectly thin oil film left on the liner bore by the oil control ring will flash off if temperatures exceed 180° - 200°C, and the piston rings will scuff. <S> This need for lubrication is the weak link which makes improving heat resistance for piston engine materials redundant. <S> Lubrication in turn requires sufficient cooling which is possible because combustion in reciprocating engines is a discontinuous process with only the end of one and the beginning of the next stroke producing compression and combustion heat while the others allow to cool down the cylinder head and walls. <S> Contrast this to jet engines. <S> Continous combustion produces much higher thermal loads so any attempt at sealing the compressor and turbine disks against the outer casing is futile. <S> Only the development of heat-resistant alloys has made this possible <S> : Look at how the improving materials allowed increasing compression ratio s. <S> Modern turbofan engines reach compression ratios of up to 50:1 while diesels are stuck at around 20:1 and gasoline engines at around 10:1. <S> Aviation pistons with superchargers raise that to levels similar to modern turbofans: <S> The Wright R-3350 <S> turbo-compound engine supercharger increased pressure by 6.5:1 with the pistons compressing air again by 6.85:1 for a total of 45:1. <S> The highest compression ratios were achieved with super- or turbocharged diesels. <S> The Jumo 205D supercharger achieved a compression ratio of 8.85:1 and the engine another 17:1 for a total of 150:1, but in all cases needing intercoolers to keep air temperature low enough and using waste gates or staged chargers to only reach the top compression ratios close to their critical altitude! <S> Since decades we can read about " adiabatic engines ", piston engines using heat-resistant ceramics and doing away with the whole cooling system. <S> Their implementation has so far not happened because the wear between piston and liner has been unacceptable (among a host of other problems, like manufacturing cost and brittleness). <A> Piston engines do not get as hot ( the metallic components) ; the exhaust gases are hot but not nearly as hot as the first stage of the turbine. <S> Remember the cylinders and pistons are made of aluminum which melts at 1000 <S> +/- <S> F and is pretty useless at 600 F. <S> The first turbine stage gases were up to 1800 F when I last read about them . <S> The high performance turbine blades have small axial holes for cooling air to flow through them. <S> And turbines are always hot while a piston engine only reaches its highest temperatures on one of 4 strokes. <S> The exhaust valves are made of high temperature alloys . <A> Piston engines are designed to produce mechanical energy, torque , which is used to move a propulsion unit. <S> In aircraft, it is the propeller, in cars, the wheel. <S> There may or may not be a transmission. <S> Heat produced is waste (after expansion to drive the piston) and is removed by a cooling system and exhaust. <S> The enclosed piston is more efficient than a jet at producing mechanical energy per unit of fuel, just as the cannon is more efficient than the recoiless rifle at propelling a shell. <S> Good <S> conductors of heat, such as aluminum, brass, and chromium steel, work well with these applications, but high fuel burn rates can lead to overheating. <S> Piston engines are RPM limited, and simply cannot produce enough power as ... Jets. <S> Capable of producing much more thrust by using heat resistant metals and running at much higher RPM . <S> Here the "internal combustion" is replaced with less efficient but lighter jet engines. <S> Jets have an "Ace in the Hole", the ability to maintain thrust at higher altitudes, where greater TAS off-sets lower propulsion efficiency. <S> This is why the 747 has double the ton miles/per <S> gallon fuel burned efficiency compared with even the mightiest of the piston engined transports. <S> Lower and slower, piston props are better.
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With pistons, combustion of fuel is not constant, allowing heat sinks such as air and water flow, to remove the heat before temperatures get too hot.
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How can a pilot become established on the KBIV, ILS or LOC Rwy 26 Approach? Consider KBIV (Holland) in west Michigan: Now consider the ILS / LOC to Rwy 26 at KBIV: Questions: There is a note on the IAP: "Procedure NA for arrival on PMM VOR/DME airway radials 004 CW 091" Does this mean only V55, V193, V274 or V170 or does it mean any radial between 004 to 091 off of PMM? There is no feeder route on the plate with NoPT. Does this mean the course reversal at JAVPO is mandatory? From experience, most of the time, it is vectors to final without a course reversal. My question is more about the charting, not the real world result, and what to do if the radar was broken that day... How do I get to KBIV? <Q> To answer question #1, you are not allowed to use this approach when arriving to the PMM VOR from radial degree numbers 004 ascending to 091. <S> This means that you can not fly in to PMM from the Northish, Northeast, or East. <S> This is probably to avoid conflict with the major congested area of Grand Rapids and its associated airport’s Class B airspace. <S> Also, V170 is no longer an active victor airway. <S> And, PMM R-29 is unusable for VOR only navigation. <S> However, this does not preclude using this approach for local flights and radar vectoring where an arrival would not be necessary. <S> To answer question #2, the course reversal at JAVPO is not mandatory. <S> It is a Holding pattern in lieu of procedure turns. <S> JAVPO is the Intermediate Fix for the approach. <S> You can use JAVPO or its associated intermediate leg as a gate for a straight-in approach on the IAP. <S> Just state your intentions and get clearance to maintain spacing and separation. <S> Wbeard52 has given a great acronym to remember when a procedure turn is not required. <S> Another one to remember is the one derived from the FAA‘s list of situations not requiring a procedure turn included in the Instrument Flying Handbook . <S> It is the acronym taught to prepare for the FAA written knowledge test and the practical checkride. <S> S.H.A.R.P.T.T. <S> S traight in approaches H old in lieu of procedure turns A <S> rc approaches R adar vectoring <S> No P t noted on the approach T eardrop course reversal approaches T imed (start) <S> approaches <S> One point to note is that a procedure turn should be planned anytime the angle inbound to join the approach will result in a turn of greater than 90°. <S> This means that flying from PMM on the 033 radial direct to JAVPO without vectoring would result in a course reversal. <S> However, you could hold on the published hold at PMM to get set up for the approach. <S> This would necessitate holding at a traditionally very busy (aircraft dense) fix, though. <S> Probably something both you and ATC want to avoid for a GA aircraft if possible. <A> I would plan to cross PMM from the west and then proceed outbound on the 033° to JAVPO and perform the hold in lieu of procedure turn and then proceed inbound. <S> ATC does not want you to fly almost 180 turn at PMM so coming from the northeast <S> is no good <S> and so it is marked NA (not approved). <S> A procedure is always required when it is charted with four exceptions. <S> Think the acronym SNoRT. <S> S - Straight - In. <S> ATC clears you using the words "Straight - In." <S> N12345 proceed direct JAVPO cleared straight-in ILS RWY 26. <S> No - NoPT on shown on a route on the instrument plate R - Radar Vectors to final. <S> N12345 <S> 5 miles from JAVPO fly heading 240° till established on the localizer. <S> Cleared ILS RWY 26 approach. <S> T - Timed approaches are in use. <S> Either ATIS will tell you timed approaches are in use or the pilot hears a time to cross the FAF and that would be a good indication that timed approaches are in use. <S> (Very uncommon) <A> This is simply saying you can't approach the VOR from the northeast and then do a 180 back to the approach. <S> Even if you could do that, you still wouldn't want to do that: why fly 22 miles past the 'IF' and then turn around? <S> That would just be silly.
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Ideally, you would either 1) simply enter and fly the hold as your entry method, 2) get "cleared straight-in" from ATC when they issue your clearance, or 3) get radar vectors to the final approach course from ATC.
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Why is the position of the pilots' head (eyes) so important? From this question: What are these Lights on Center Holm between Windows on the A320? I learn that the pilots' eye position is important. Enough to justify an extra piece of equipment. But why? Can't a pilot tell if they see enough, above/below/on each side, by just looking? <Q> This is important when hand-flying the aircraft to ensure consistent landings. <S> Having a consistent viewpoint gives several operational advantages such as easing the handling of the aircraft by providing pilots with a consistent visual reference, repeatable at every flight. <S> This is especially useful during final approach to be familiarized with the final approach path angle and also for the flare phase. <S> Best forward visibility , which maximizes the area in front of the aircraft you can see (Visual Segment): Having the seat further backwards or lower would reduce the Visual Segment. <S> Good View of the Instruments , which allows seeing the PFD and ND without having to move your head down. <S> This is how it looks with the correct seating position: <S> And this is how it looks if you are seated too high or too far <S> forwards: <S> All sources: <S> Airbus - Are You Properly Seated? <S> You also asked <S> Can't a pilot tell if they see enough, above/below/on each side, by just looking? <S> Yes, not all aircraft have the three balls for finding the optimum seat position. <S> You can do it by looking over the glareshield and ensuring good visibility of the PFD/ND. <S> On Boeing aircraft, this is how it is supposed to be done since they don't have a dedicated eye reference indicator: <S> Pilot Seat Adjustment Adjust the seat position with the appropriate controls to obtain the optimum eyereference position. <S> Use the handhold above the forward window to assist. <S> Thefollowing sight references are used: Sight along the upper surface of the glareshield with a small amount <S> ofthe airplane nose structure visible (A) <S> Sight over the control column (in the neutral position) until the bottomedge of the outboard display unit is visible (B). <S> (Boeing 737 NG FCOMv2 - 1.40.44 Airplane General - System Description) <A> It's just a shortcut aid based on the OEM's ergonomics engineering. <S> The sweet spot is considered to be with your eyes high enough to see down to the base of the windshield without obstructing anything on the instrument panel. <S> This puts your preferred sight line roughly on the plane of the coaming/glareshield extending toward you from the base of the windshield (or slightly above or below), when the seat is positioned to the typical for/aft position for a comfortable hold on the control wheel (roughly a forearm's length from your torso). <S> When you get in there are 3 steps: <S> Set the seat for and aft to suit your forearm length to the control wheel or side stick. <S> Set the seat height to align the balls, or whatever your personal preference is. <S> Set the rudder pedal adjustment (called the stature adjustment) to your leg length, making sure you can apply full rudder plus push the brake on that side fully on with your toe while your leg is stretched out. <S> Not everybody likes the recommended location set by the balls. <S> When I was flying CRJs, which had the balls on the center post, I would ignore them most of the time and just set the height to put my sight line where I could just see the top surface of the glareshield, which, as it happens, more or less aligns the balls. <S> The eye height most pilots will set with or without the balls tends to be the same, and the seat setting you find when you get in tends to reflect the torso length of the previous pilot. <S> I have a long torso and short legs, kind of orangutan-ish, so <S> the next person after me usually would find the seat set pretty close to the floor. <A> To answer the second part of your question, the short answer is ‘No’. <S> We use perspective to judge taxiing manoeuvers (turns) and to achieve the correct initial pitch attitude on take-off and on landing. <S> We need certain visual cues to determine correct positioning over the threshold of the runway. <S> When perspective is used, a reference point is needed by which to gauge your position. <S> That reference point must remain the same the entire time. <S> An example: On take-off in poor visibility, we need to see 4 runway lights to confirm whether or not we can depart. <S> An incorrectly adjusted seat could mean a delayed take-off or an illegal one. <S> Another example: On landing, at 50ft we need to see the threshold disappear under the nose. <S> This helps to ensure that we are neither too high nor too low (both of which can lead to disaster). <S> Adjusting seat height alters that visual cue with potential serious consequences. <A> Airplane designers analyze and test the heck out of the airplane-pilot system. <S> That very hard problem becomes less hard if they remove the flexibility of where can the pilot eyes be.
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The correct seating position is important to ensure A consistent viewpoint , which results in the final approach and flare always looking the same to the pilot.
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how can i help the air force at this age if I'm only 13 years old? I'm young, 13 to be exact. I'm not old enough to join and I really want to help the brave men and women in the skies.How can I help the air force at this age? <Q> So is the Civil Air Patrol . <S> Both will give you a taste of armed uniformed services life. <S> Otherwise, look into volunteer opportunities locally to support the armed forces. <S> Military.com may be a good start on researching charity organizations. <S> Just be respectful in the forums, please. <A> In the US, you could look into Junior ROTC for the AF. <S> https://www.airforce.com/frequently-asked-questions/high-school/what-is-jrotc <A> Study. <S> Strive to become educated. <S> Hone your intelligence. <S> Learn science, engineering, and technology. <S> There are two reasons for this: <S> The Air Force is a technical service, dependent most upon enlistees who are strong in science and technology. <S> The air force prefers their enlistees to have degrees, and the more demanding jobs in the Air Force are filled by those with advanced degrees. <S> For example, test pilots tend to have advanced engineering degrees. <S> The Air Force is expensive to maintain and depends upon a fair amount of tax revenue. <S> If you do not enlist in the Air Force, but have developed strong engineering and science skills, you will have a higher than average salary that provides higher tax revenue to the government. <S> The government will have more tax revenue to buy the airplanes and other systems that make the Air Force work for those who did enlist. <A> In the UK, you can join the RAF Air Cadets at age 13 or older. <S> If you want a more civilian route at first, then there's also the Air Scouts <A> There's probably little that you (or anyone) can do to help the Air Force directly without going through the training required to join as service personnel. <S> There is, however, another route. <S> They may have a branch local to you that would welcome your enthusiasm. <S> Alternatively, there are many organisations supporting service veterans who could use your help. <S> Take a look at Charity Navigator to find organisations that do what you're interested in, and contact their local branches.
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Whether you enlist or not, strengthening your own mind and your own knowledge of science and technology will help the Air Force. You could contact the Air Force Aid Society , a charity that provides support to the men and women of the air force to help with their non-operational needs (education, healthcare, housing, etc.). As stated by Crossroads, AFROTC is an option.
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Why are the guns on the AC-130 not mounted on the underside of the aircraft? Why must the guns of the AC-130 be on the side forcing the plane to circle the target. Would it not be more practical to have the guns underneath the plane shooting downwards? <Q> By putting the guns on the side, the gunner can direct a continuous stream of bullets at the intended target for as long as the pilot wishes to continue circling it. <A> The C130 is a cargo aircraft. <S> The AC130 is the airframe converted for use as a gunship, of which there are several variants. <S> Guns under an aircraft are usually found on helicopters, mounted on turrets. <S> WW2 bombers like the Flying Fortress worked more like the AC130, and had gunners in various places including a belly mounted turret. <S> The low load floor of a cargo aircraft precludes placement of guns there. <S> Additionally, the AC130 carries multiple guns . <S> 7.62 Minigun, 25mm Gatling gun, 40mm Bofors cannon, and 105mm howitzer have all been used. <S> Simultaneous use requires multiple mounting points. <S> Same side placement means they can all be used on one target. <A> The original concept of the AC-130 gunship was to loiter over an area for an extended period of time in support of ground troops. <S> It provides close air support when precision is needed instead of indiscriminate strafing runs of fast movers like F-4s and other jets. <S> Using a ground reference maneuver called turns on pylons and pivotal altitude keeps one side of the gunship perpetually aligned with a target on the ground as the aircraft circles it. <S> You can find more detail on the Smithsonian Channel show Air Warriors . <A> This is called "loitering". <S> This is the primary use-case for the AC-130: it's basically a flying artillery position, not a flying tank. <S> Having guns point downwards will have the guns point away from the target (due to banking) when loitering. <S> Making it unsuitable to be used as a flying artillery position and forcing it to behave like a bomber (flying, reusable "bullet/shell"*). <A> I think you've got this the wrong way <S> round - you don't fly in circles because the guns are on the side; the guns are on the side because you have to fly in circles. <S> The only way to get a fixed-wing aircraft to loiter over a particular spot is for it to fly in a circle. <S> To do this you have to bank <S> the aircraft (i.e., tilt it on its side). <S> If you do this, you automatically present the side of the aircraft to the target, so it's the natural place to position your guns. <S> If you put them on the belly, you'd have to then aim them to the side - as far as they would go. <S> This side-firing strategy grew out of a technique developed by the British Chindits in Burma in WW2. <S> They used small fixed-wing aircraft for supply and evacuation. <S> The planes could not land in the jungle, so flew tight orbits over a clearing and lowered supplies on a rope. <S> They then hauled up casualties the same way. <S> In the Vietnam War, the Americans had the idea of replacing the rope with a line of fire and the gunship was born.
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If the guns were belly-mounted, the pilot would have to make multiple passes at the target zone from different directions, with long pauses between them- long enough for the enemy soldiers to reposition themselves and escape. Purpose built aircraft usually integrate guns into the wings (fighters) or fuselage (A10). Because the AC-130 is an airplane, not a helicopter, the only way to "hover" over a target is to fly in a circle around the target.
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Is there any benefit of using a swept wings at low-subsonic speeds? Is there any benefit to using swept wings for speeds up to 250km/h ? (By the way..Why do some fast birds like falcons, swifts and most migratory birds use swept wings or raked wingtips since they fly at low subsonic speeds?) Peregrine falcon - swept wings Alpine swift - swept wings Albatros - straight wings with raked wingtips Common swift - straight wings with raked wingtips <Q> Birds adjust wing area by pulling in their humerus and ulna <S> so the wing sweeps first forward, and to compensate for that, have to sweep their outer wing backwards which is accomplished by folding the digits backwards. <S> Instead of adjusting lift coefficient, they adjust wing area to not expose more surface to air friction than necessary. <S> The picture below shows how the wing is opened for maximum lift at low speed. <S> As Zeiss Ikon correctly observes, folding the digits back and fore is the bird's way of pitch control, so the sweep is a consequence of pitch control, not aerodynamics. <S> Red-tailed Hawk, captive bird, Bacara, Santa Barbara, California. <S> By Steve Jurvetson / CC BY ( https://creativecommons.org/licenses/by/2.0 ) <A> Swept wings may be useful to adjust the center of lift when, for instance, a change in power plant or other equipment has resulted in an aft center of mass location, or when it's desirable to allow additional after cargo storage. <S> They can also provide roll stability similarly to dihedral when flying at significant angle of attack. <S> Birds that have wing sweep generally seem to have the ability to vary this condition in flight -- which they appear (to my eye -- I'm not an ornithologist or even a bird-watcher) to use similarly to managing center of lift as above. <S> In fact, almost all birds do this to some extent, along with tail movements, for pitch control. <A> I was shown a hang glider with mild sweep to the wings, and a few degrees of tip washout, that is, the angle of attack was slightly lower at the wingtips (maintained by tensioning the rigging, I think). <S> The idea of the washout was that the central part of the wing stalled while the wingtips (with lower AOA) were still flying. <S> And the idea of the sweep was that the wingtips being aft of the centre section, the centre of lift moved aft when that happened, allowing the nose to drop, automatically recovering from the stall. <S> So, sweep can be used to help stability, and I'm pretty sure that hang glider stayed well below the transonic region. <S> EDIT : <S> Tip washout and mild sweep visible here around 0:40 and 1:20 , and clearly low Mach number. <A> Swept wings increase something known as the critical mach number. <S> When air travels over the top half of an airfoil, it gains speed. <S> If the incoming air far upstream from the wing is at a high subsonic speed, the speed gained as it travels over the wing can induce transonic, sonic, or even supersonic flow which can lead to unpredictable wing effects such as control reversal and loss of control as the P-38 pilots of WWII faced. <S> Also check out supercritical airfoils which delay mach effects as well. <S> Hope this helps!
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Swept back wings increase the amount of span-wise flow, decreasing the amount of velocity that the air picks up as it travels over the airfoil and allowing the wing to fly closer to the speed of sound.
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Could propeller wash provide sufficient lift to take off - even in theory? I know this seems a crazy thing to ask but it is not the same as lifting oneself by the bootstraps. If you try to lift yourself that way, there are two equal and opposite forces, yet there are experiments with muscle powered planes that work. So, provided the plane was stabilised somehow, and the wings were designed for the purpose, could propellor wash theoretically lift the plane? If not why not? Note I understand that a normal plane would start to move forward. Please assume that the plane is restrained from the rear by a cable and that the experiment takes place in the absence of wind. <Q> Yes. <S> The wing doesn't care what is causing air to flow past it. <S> Headwind, propwash, 747 wake, gopher sneezes. <S> If the airplane is restrained from forward motion, and the propwash over most of the wing is fast enough, let's say more than the airplane's stall speed, then the wing must generate enough lift to support the airplane, causing it to take off. <S> It's not so much a matter of designing the wing specially, as making the airplane tolerate the many large props needed, and the weight of the engines. <S> That much power is too much for efficient cruise. <S> But it's easy to implement with a one pound model airplane. <A> In principle yes, but why would you do it? <S> For vertical take-off this would be grossly inefficient. <S> Lift is produced by deflecting air downwards . <S> This becomes easier as more air is available for deflection since the amount of deflection needed for a given lift can be reduced. <S> However, when all air movement is provided by the propeller, why reduce efficiency by blowing it horizontally over a wing, where it creates friction? <S> Wouldn't it be better to direct this airflow directly downwards <S> so no further deflection is needed? <S> Any deflection will incur losses, so taking the detour over the wing complicates things needlessly. <S> That does not mean this hasn't been tried –as qq jkztd points out in the comments, the Ryan VZ-3 used this concept, albeit with poor results. <S> Ryan 92 VZ-3, rebuilt after the crash (picture source ). <S> For a theoretical approach the propeller diameter would need to be as large as the half span of the aircraft, with both propellers mounted at mid span. <S> Now the landing gear also needs to be longer than quarter span in order to let them spin freely. <S> Next, the wing needs flaps which are able to deflect the flow of air by 90° which will involve some active blowing. <S> This becomes quite complex quickly, so a design like the one below looks more promising: Vertol Model 76 VZ-2 <S> (picture source ) <S> was the first tilt wing design which successfully transitioned between vertical and horizontal flight and was built for the same purpose as the VZ-3. <S> While not any more visually appealing than the VZ-3, it had a longer career: It flew first (in 1957 as opposed to 1959 for the VZ-3) and was used until 1965 while the VZ-3 was retired in 1961. <A> Restricting the question to approximately horizontal airflow ... <S> it's been tried. <S> The Custer Channel Wing was one that tried ... <S> it didn't quite make it, but was claimed to be able to fly at 8 to 11 mph. <S> That may have been optimistic but the CCW5 (pictured : image from linked Wiki) apparently flew as slow as 35mph. <S> And it keeps being tried... <S> this time in conjunction with the Coanda Effect ... results not reported so far. <A> Absolutely. <S> Here's what it looks like: <S> It's a turbojet here (this is an F-35 engine) but from a physics standpoint there's no reason you couldn't do it with a propeller. <S> So long as you have some means of directing a sufficient portion of the thrust downward, you can lift off. <S> An airfoil would also redirect the thrust slightly downward, but far less efficiently than a nozzle. <S> The physics works though, if your engine can produce enough thrust to get the required downward component. <A> Presumably you are referring to using wings fixed to the airframe with props driving air over them. <S> If instead you move the wing through the air to create airflow over it you "cut out the middleman" and end up with a helicopter or typical multirotor craft. <S> Similarly an ornithopter moves the wing through the air to attain lift.
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This wouldn't be even remotely practical with a normal engine and airfoil.
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Why don't turbofan engines have shrouds affixed to the fan blades? For a turbofan to be efficient the gap between the blades and the shroud has to be extremely small. Why don't we just attach the shroud directly to the blades and let it spin as one? Would that decrease the efficiency of the fan or is it just not structurally sound? <Q> This has actually been done, at least on the CFM-56 series at some point. <S> The image is taken from here , the article is about the F108 engine which is the US military version of the CFM-56. <S> In newer versions of the engine the blade-tip shrouds have been replaced by mid-span shrouds as below (from Wikipedia), or have been removed. <S> As pointed out by Camille Goudeseune, turbofans have to accomodate a lot of situations, and a blade-tip shroud adds a lot of mass and therefore increases loads in the blade, further reducing fatigue life. <S> Among the advantages of this configuration that were not mentioned in the question or in the other answer is that shrouds help reduce vibration amplitudes through frictional damping. <S> This explains why mid-span shrouds are still in play in several engines, while these do not participate in reducing blade-tip losses. <S> Finally, while this configuration is seemingly not used anymore on fan blades, it is still used in other parts of modern engines, specifically the turbine module. <S> As an example, the picture below is from the GE9X website , see the Low Pressure Turbine blades. <A> Land-based turbines sometimes use rotating shrouds, with something like a https://en.wikipedia.org/wiki/Labyrinth_seal to reduce leakage. <S> So it's structurally sound in principle. <S> But turbines in airplanes have to tolerate nonaxial loads, foreign object ingestion, and a broad range of ambient temperature, pressure, and humidity. <S> Better to bang up a few blades than to lose the whole rotor. <S> That would outweigh even a few per cent improved fuel efficiency. <A> To add to the fine answers: The rotating shroud woud add extra mass, as the duct would still have to run past it. <S> This mass would also be rotating at high speed, creating substantial gyroscopic forces, and on top of all that, making the engine less responsive. <S> Then there are the constructional issues: although not at all impossible to engineer, <S> as there are some implementations, the structure would not be as simple as one might think. <S> High rotational speeds, bending of blades, vibrations etc would have to be taken into account and dealt with. <S> Balancing a huge rotating disk would definitely be a pita. <S> there is a Q&A somewhere here about balancing fan blades, I'll try to remember and find it and add it here: adding a disk around the blades would not make the equation simpler. <S> A wide operational temperature range does not help either. <S> We are talking maybe from + 60 <S> ° C all the way down to - 70 <S> °C <S> All in all, there is a lot of dynamics involved with fan blades, best keep the construction as simple as possible.
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Affixing the blade tips to the shroud may not tolerate such abuse well, in terms of not exploding, or surviving the next hour, or lengthening the interval between engine overhauls.
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Are there any GA trainer aircraft without toe brakes? I'm a student pilot, and I've built about 20 hours on a Cessna 172. I also have an old ankle injury that makes it hard to bend my left ankle, and I'll probably be getting an ankle fusion later this year. I know I won't be able to work the left brake with a fused ankle. Are there any good options for trainer aircraft with other kinds of brakes? <Q> There are still many Ercoupes in the fleet that don't even have rudder pedals, never mind toe-brakes on the rudder pedals. <S> You may also want to consider arranging for a more commonly-available trainer (e.g. Cessna 152, Piper Tomahawk, Diamond DA20, etc.) to be equipped with hand-controls for braking. <S> This is done for individuals who have any number of reasons that they can't operate the rudder pedals with their feet, such as paraplegia, deformity, etc. <S> See e.g. https://www.freedomintheair.org/hand-controls/ , https://www.newmobility.com/2019/01/pilots-planes-hand-controls/ , https://www.wired.com/2009/08/hand-control-airplanes/ , https://abilitymagazine.com/hand-controls-for-flying/ , etc. <A> The latter is quite common in the US, but being an aerobatic airplane, it may not be very suitable for your experience. <S> The Australian Jabiru light GA aircraft have a brake handle on the central post between the pilots. <A> The 1964 Piper Cherokee that I rent has inoperative toe brakes. <S> In order to stop the aircraft after landing, you have to slow down past the maximum taxiing speed using aerodynamic braking. <S> Then, you use the parking handbrake to come to a complete stop. <S> I have never had to make an actual soft or short field landing with this aircraft. <S> But, it would be challenging. <S> Personally, I would avoid it. <S> It might be even harder in a Cessna 172. <S> I have not flown one with a handbrake as responsive as that Cherokee.
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Russian/Soviet GA trainers Yak-18T and Yak-52 have a manual brake handle on the yoke/stick.
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How is reduced alcoholic beer made? How is low/no alcohol beer made? I'm assuming that the beer is made normally and the alcohol is then removed, is it any more than just boiling it off? I've noticed that no/low alcohol beers' taste improved hugely a few years ago, is this due to a new technique? <Q> There are a couple of ways to do that. <S> The two main "approaches" are to extract the alcohol afterwards or just don't allow the generation of it. <S> The extracting part can be achieved by filtering and reverse osmosis. <S> Alcohol and water are getting sucked out and the "beer mass" gets re-watered. <S> These steps may affect the taste quit a bit. <S> A few brewers (especially in Germany) have developed a "top secret" technique to brew a alcohol free beer which tastes the same as "normal" beer - but most of these are "top secret". <S> Latest science experiements revealed a new way of brewing alcohol free beer, by just stopping the fermentation process. <S> This can be done by lowering the temperature of the liquid containers. <S> Beers brewed with this technique tend to taste more sweet. <S> Both method have their up and downs <S> so a couple brewers combined both: Less fermentation than usual and extracting the extra bits of alcohol. <A> I recently went on a tour of a microbrewery and had a conversation with a brewer afterwards. <S> It may be worth noting that the beer he was talking about was not designated for drinking, but for use in food production (beer-battered fish sticks, anyone?). <A> Reduced alcoholic beer has been developed by using an advanced development of the process known as vacuum distillation at low temperature (which is the most traditional and is less aggressive of any alcohol extraction methods), by using this sophisticated process the beer doesn't suffer any temperature or pressure aggression.
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He said that their approach for reducing the alcohol content to legal "non-alcoholic" levels was to simply dilute regular beer with purified water.
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What temperature should I serve my beer? In general, what's the best way to work out the temperature at which to serve a particular beer? Room temperature? Cold? Supercold? Warm? <Q> It depends on the beer really. <S> A good rule of thumb is darker beer should be served at a warmer temperature than lighter beer. <S> For instance if you refrigerate all of your beers and then pull them out of the fridge and drink them instantly you will miss A LOT of the flavor complexity of pretty much every stout and porter you put to your lips. <S> But, if you let the dark stuff warm up for just 15 minutes before you drink it (let it sit at room temp) <S> a bunch of new flavors will appear that you never would have noticed otherwise. <S> This doesn't work so well, in my experience, for lighter beers like pilsner, lager, or hefe-weisen. <S> They really are meant to be drank cold and letting them get warm changes their flavor profile for the worse. <S> Obviously there will always be personal preferences but, at a minimum I encourage you to try letting your darker beers warm up just a bit and see what a positive difference it makes. <S> Here is a temperature guide from this article: Serving Temperature Guide . <S> It categorizes different beers based on temps to serve at. <S> These are basic rules of thumb and again you'll want to experiment and discover what temps you like your beers at the best. <A> As stated earlier, temperature is a matter of taste regarding beer. <S> German-style lagers are almost exclusively recommended to be served no lower than 6°C (43°F)no higher <S> than 9°C (49°F), <S> but I often find that the last (and warmest) mouthfuls from a glass actually have the most flavour - <S> but I would always start with the lager cold when possible. <S> Real ales are a different story. <S> On the continent of Europe there still seems to be a myth that British drink their beer 'luke-warm', but if served at that temperature most Brits would complain (and maybe continue to drink it while complaining). <S> I believe the phrase 'serve cool' rather than 'cold' applies. <S> Some live, bottled beers actually suffer from being too cold. <S> On of my favourites, Black Sheep Ale develops a 'chill haze' - going a little cloudy if left in the fridge too long. <S> 13 <S> ° <S> C (55°F)is about right for such beers. <S> Reference the book Beer For Dummies! <A> Personally as a rule of thumb I would allow my choice to be dictated by the level of carbonation in the beer. <S> Temperature affects how rapidly carbon dioxide dissipates from the beer, so the more carbon dioxide it starts with, the colder I would serve it, in order to preserve it in its intended state for as long as possible. <S> My personal taste would also entail a slightly cooler temperature for pale ale styles (lighter in colour and body and hoppier) and slightly warmer for brown ales, bitters, stouts and so on. <S> I would also like to register my objection to the term 'warm' used for beer. <S> I don't know of any drinking culture that really does encourage the warm serving of beer in any normal understanding of the word. ' <S> Warm' really refers to cellar temperature rather than refrigerator or just-above-zero temperature. <S> A similar temperature to that you'd expect in red wine would be appropriate for the 'warm' beers. <A> A site that has a lot of useful information is craftbeer.com . <S> By going to the beer styles section, you will see the beer style information, including serving temperature. <S> If you want to go more in depth, you can get training from Cicerone . <S> They are a company that train bar staff on the the correct way to serve beer (temp, glasses,food pairing, etc) as well as information about the beer styles, brewing process and more.
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Necessity may also play a part (Given a choice between a warm beer vs no beer it depends how thirsty you are!).
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What is the difference between an ale and a lager? Apart from coming out of different taps, some ales seem very similar to lagers (although there are clearly a much greater variety of ales). Is there a difference in the way they are made? <Q> Ale yeast strains are best used at temperatures ranging from 10 to 25°C, though some strains will not actively ferment below 12°C (33). <S> Ale yeasts are generally regarded as top-fermenting yeasts since they rise to the surface during fermentation, creating a very thick, rich yeast head. <S> That is why the term "top-fermenting" is associated with ale yeasts. <S> Fermentation by ale yeasts at these relatively warmer temperatures produces a beer high in esters, which many regard as a distinctive character of ale beers. <S> Top-fermenting yeasts are used for brewing ales, porters, stouts, Altbier, Kölsch, and wheat beers. <S> * Lager yeast strains are best used at temperatures ranging from 7 to 15°C. <S> At these temperatures, lager yeasts grow less rapidly than ale yeasts, and with less surface foam they tend to settle out to the bottom of the fermenter as fermentation nears completion. <S> This is why they are often referred to as "bottom" yeasts. <S> The final flavour of the beer will depend a great deal on the strain of lager yeast and the temperatures at which it was fermented. <S> Some of the lager styles made from bottom-fermenting yeasts are Pilsners, Dortmunders, Märzen, Bocks, and American malt liquors. <S> * <S> (All information from BeerAdvocate .) <A> A pictty good summary: <S> (Source: BeerSci: <S> What Is The Difference Between A Lager And An Ale? ) <S> The first part of the picture depicts the description in my answer about where the yeast "works," the temperatures at which they work, and then some common types of ales/lagers. <S> The second picture shows S. cerevisiae (common ale yeast) and a wild yeast S. eubayanus making some new cold tolerant yeast strain babies that are the common lager yeast (S. pastorianus). <S> Note: my biology is rusty but from my reading and looking at the picture, this is what I derived. <S> (From @Grohlier's comment) <A> This is pretty good explanation <S> Source: <S> Twenty Things Worth Knowing About Beer. <A> Ales and lagers are brewed with different types of yeast. <S> Ale yeast ferments at the top of the brewing vat at a comfortable room temperature while lager yeast ferments at the bottom of the vat at a lower temperature. <S> The "low and slow" lager fermentation brings out more complex flavors. <A> You may hear the terms <S> "top-fermenting" for ale yeasts and "bottom-fermenting" for lagers, <S> but I think that's more-or-less happen-stance -- <S> the yeasts themselves are not inclined toward a particular altitude. <A> The main difference between the two is the different types of yeast that they both use. <S> Lager yeasts are more tolerant to cold temperatures and so are fermented at a lower temperature. <S> This is what gives the lager a crisp flavour. <S> The ale yeasts ferment at higher temperatures and take less time to complete as the yeast is more active the higher the temperature. <S> Both types also use very different hops and malts... <S> Source: http://www.homebrew-zone.com
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The primary difference is the yeast used to ferment the beer -- ales use yeasts strains which work at a warmer temperature (10-25 deg C) than lager yeasts strains (7-15 deg C).
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Do IPAs cause worse hangovers? I usually drink strong Belgian Ales, particularly Triples, Quads and Trappists, so I'm no stranger to strong beer. But I've noticed that I get far, far worse hangovers when drinking IPAs. Is there anything about IPAs that would make this possible? The lower quality places like ask.com or Yahoo answers usually say no, that only ABV produces hangovers, though one source did seem to imply that IPAs have special ingredients that make this a possibility. So I want to ask the experts here: do IPAs have ingredients that other strong beers lack, that could exacerbate hangovers? <Q> Although as Bill said it can be down to a persons chemistry. <S> One reason for you finding that IPAs affect you more could be the higher hop content in a Pale Ale (IPAs in particular). <S> Hops (the oils) can have an effect on brain chemistry, that affect can be positive or it can be negative! <S> Some people can actually have alergic reactions to hops, or even beer in general (poor them, see this ). <S> Where as I suffer from some nasty migraine problems and actually find that well hopped ales alleviate some of the symptoms (not that I use it as a reason to drink!!). <S> So to sum up is it possible that you find that IPAs cause you to suffer more in the morning because you have a slight intolerance to higher hopped beers. <S> Where as your fellow drinkers do not. <A> As stated many times above, it's very personal on what affects you and how much or how little. <S> Also, 13 of the big bottles of Franziskaner in a night makes me want to die the next day. <A> IPA's don't have any real negative impact on me in terms of hangovers but Budweiser (as a prime example) has a much faster onset of hangover for me <S> and I suffer far worse from it. <S> The "Ice Beers" that became popular in the early 90's really caused me to have a lot of problems <S> but, again, IPA's of all stripes typically don't bother me at all. <A> I think there is probably some truth to the general responses here. <S> I too am a big IPA fan and when I first started drinking them, I had no major issues with hang overs, outside of the fact that they have a much higher gravity. <S> My own experience over the last year is that I've witnessed a peculiar tendency to get very clogged sinuses the morning after just a handful of IPAs (really any brand). <S> This it to say that the reaction is due to something in the beer other than the alcohol, because less hoppy beers do not offend my sinuses as much. <A> Could this perhaps have do do with the way people tend to drink these particular styles? <S> In the circles I run in, Belgian- and Trappist-style beers tend to get revered, pondered, and savored, and thus drunk more slowly and possibly in lower quantities than IPAs, which are more plentiful, generally cheaper, and tend to get pounded by the six-pack next to some hot wings or a cheeseburger.
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Dry-hopped beers seem to give me worse hangovers. I suspect this really boils down to each persons' chemistry.
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Do different beer glass shapes really make a difference in taste? I understand the basic distinction for wine glasses: red wine glasses are shaped to help keep some of the aroma inside the glass, whereas whites don't. But shapes for beer glasses, such as pilsner vs a standard pint glass, just seem to be an aesthetic difference. Yet I've had people insist that glasses make a big difference for things like Belgian beer. Is there a sound reason to use the "right" glass for each kind of beer? <Q> Yes. <S> Taste is really smell, and different glasses can capture aromas differently. <S> Furthermore, different aromas may be more or less present dependent upon temperature, and a glass may be crafted to be held a particular way (gathering more or less heat from your hand). <S> The same is true for wine glasses. <S> That said, how much of a difference it makes to you <S> is what's important. <S> Going back to the wine comparison, I can sometimes tell the difference between different glasses, but not consistently. <S> So it's not the most important thing. <S> Now that <S> that's said, there has been some informal, perhaps less than perfectly scientific studies, including a blind test . <S> Beer advocate provides some more detailed information . <S> Some of my local bars carry stemware for specific European beers, and I know of one stateside brewery, Black Shirt Brewing in Denver, which really wants you to stick your nose up in it (to good effect, in my experience). <A> I would like to point out that taste is not the only important criterion when drinking beer. <S> What you want is a good experience , and the taste is only a part (albeit a major part) of that. <S> Having different glasses for different types of beers can affect your drinking experience in a number of different ways. <S> First off, having an unusual or unique glass can often be very fun, because it's probably not something you're used to. <S> The first time I ever drank beer from a litre mug was a very fun experience for me, and not because it made the beer taste differently. <S> Secondly, I find that different types of glasses encourage me to enjoy the beer in different ways. <S> I find that glasses with stems, which are often used for stronger beers, encourage me to drink the beer more slowly and savor it a bit more than a glass without a stem. <S> I think these effects on experience are one of the big reasons for the wide variations in beer glassware. <S> As a beer manufacturer, if I could make a unique glass that will better help people remember my beer, I would consider that a worthwhile investment. <S> I'm not trying to say that the effects of glassware on taste don't exist or are unimportant; I think they are important. <S> But they're only part of the story. <A> As a Belgian I am always told by bartenders and brewers that for special (heavy) Belgian beers a Tulip glass is a good choice, except for Belgian Lambics (nl:Lambieken) for which one should use a flute glass. <S> These glasses are sometimes scratched at the bottom to better accommodate the bubbling (for example: Duvel Glasses) <A> Studies have shown a correlation between a foods presentation and the perceived goodness of the taste. <S> 1: <S> Arch Pediatr Adolesc Med. <S> 2007. <S> DOI:10.1001/ <S> archpedi.161.8.792 2: <S> Physiology & Behavior, 2007. <S> DOI:10.1016/j.physbeh.2006.12.010 <A> I spent many years in Germany and other European countries drinking many different types of beer... <S> I can tell you, for me, a Pilsner is best served in tall thin glasses, export beer in mugs, preferentially stein type and wheat beers in flute style glasses.... <S> taste, aroma and the expereince is all different with these glasses... <S> oh and for general knowledge, fruits and other flavors only ruin beer....
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So even excepting the usual reasons for matching a beer style to a glass style (head retention, aroma dispersal, etc.), presenting a beer in a good looking vessel will enhance its taste.
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What's the difference between a porter and a stout? Porters and stouts seem very similar and sometimes stores and restaurants group them together as if they're two different names for the same thing. Is there a difference and what is it? <Q> Beer Connoisseur Online answers this pretty thoroughly in an article . <S> The TLDR: is that "...originally a stout was a strong version of a porter. <S> Today, the difference is whatever you want it to be." <S> For an interesting history on the term Stout and the style of beer, you can check out this history of stout article provided by Eric Deloak. <S> Similarly you can read a history of porter article written by the same author: Gregg Smith <A> As such, you end up with more burnt toast and coffee type flavors in a stout, but the amount and type of roastiness depends upon the type of stout. <S> If you get the chance, try a side-by-side comparison between the regular Guinness and the Guinness Foreign Extra stouts where the regular Guinness comes off more roasty than the Foreign Extra. <S> Most porters have little to no roastiness. <S> I think of them as having more smoother chocolate-type flavors, and to be lighter in color (deep red or ruby as opposed to black), but there is a lot of overlap in the Venn diagrams between the two. <A> Well, that style thing is complicated because in real world people just make beer, and don't make beer to satisfy styles guides (at least, not until very recentely when some people started to care more about style guidelines than the beer itself). <S> Anyway, what I think is important to be aware is: <S> Many styles have a long and old history, often centuries, and what we have as one nowadays doesn't have much to do with what it was once ago. <S> Styles change a lot over time as well. <S> I'm not a specialist, but I think before the american craft beer revolution and revival in the early 80's, no one was gathering and classifying beer styles in a guide like BJCP. <S> And that same revival brought back to life many dead styles in different fashion (well, look the case of IPAs), by the way. <S> Generally, despite style guides, people have their own understanding of what is X or Y, and when naming their beers, they will do it based on their perception and references too, not strictly style guidelines. <S> If you look closer, porter and stout are ancient reference styles for more specific and contemporaneous styles ( <S> sweet stout, dry stout, outmeal stout, brown porter, robust porter, russian imperial stout, etc). <S> So, I think it makes more sense telling the difference between a milk and an outmeal stout, or brown and baltic porter than stout X porter. <S> For what's worth, for me, there's no difference between stout and porter. <S> What I mean is, at least not so that we, as consumers, can trust and be 100% of what you are going to get if you choose one over the other, specially when the name is generic like that. <S> What I think is enlightening is to understand the history of those related styles and how they came to be what they are today. <A> BJCP style guides aside, I generally love porters and don't care for stouts. <S> The latter (in my experience) tend to have a much more pronounced roasted malt character. <S> (I do like most milk stouts though, now that that's a thing)
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There are a number of different types of porters and stouts, so it isn't necessarily a simple answer, but I would say the use of roasted grains in stouts, particularly roasted barley, is the biggest difference.
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Why are some beers non-vegan? Some beers (for example, Guinness) are marked as 'not suitable for vegans'. What is in the beer such that this is the case? <Q> There are two main ingredients in beer that might cause them to be unsuitable for vegans. <S> The first one might be fairly obvious. <S> Honey is sometimes used as a sweetener, especially in meade, but certainly in other beers. <S> However, the main cause is a fining agent called Isinglass that is made from ground swim bladders of fish. <A> Guinness is popular example: isinglass , a swim bladder, is as a filter or fining agent. <A> In addition to the answers given above, some specialty beers include animal products as well. <S> I have had beer made with oyster broth for example. <S> That one is definitely not vegan. <S> Interestingly in the Middle Ages, they used to brew with chicken broth sometimes, and some other times with dairy products (including either milk or whey). <S> That is worth remembering in terms of why some specialty beers include meat products as well. <A> As you might expect, it's all got to do with the ingredients. <S> I'm a vegetarian myself, but not a vegan. <S> So I do eat honey and dairy. <S> With that said, some beers would not be considered vegan if they use those ingredients (milk stouts for instance use lactose). <S> However, an example of a non-vegetarian beer would be the oyster stout, which uses oysters in the brewing process.
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Some beer use animal by-products in their production.
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Why is drinking beer after wine a bad idea? As the well known rhyme reminds us, drinking beer after wine is a bad idea. Having made the mistake during my student years more than once and regretting it, why is it that consuming these two beverages in the wrong order causes such effects? <Q> Beer contains a lot of CO2, and CO2 causes the alcohol to 'hit to the head' much faster. <S> This is why champagne has such exhilaration (Rausch) effect. <S> It's not a good idea to drink any high-CO2 drink after drinking wine or stronger alcohols, and even more discouraged is mixing carbonated water with vodka, for example. <S> Many people have heavily regret such mixing. <S> As well, it is said you should never drink lighter alcohols after stronger. <S> You can start with beer, than after an hour/2 drink some wine, rest and drink vodka. <S> Never opposite. <S> But the best is to keep one genre of alcohol on one evening. <S> At least so are saying people in Poland. <A> I have never seen anything solid backing up any rhyme that encourages a particular order. <S> When it comes to intoxication, there are two things that are definitely relevant: <S> The total amount of alcohol consumed How fast the alcohol is absorbed As far as I am concerned, the rest is hearsay and folklore. <S> There may be some auxiliary "explanations", like people who mix types being more likely to drink more overall, and people drinking different types of alcohol at different rates at different stages of intoxication, but these are not chemical qualities. <S> Here's one NYT article backing this up . <S> I'm having a hard time finding credible scientific articles about intoxication. <A> EDIT to add sources (original answer below) <S> Mythbusters address this in episode <S> 127 - http://mythresults.com/dirty-vs-clean-car - <S> the rate of consumption is what matters, not the order <S> A hangover caused by beer is less severe than one caused by a mixture of beer and liquor. <S> BUSTED <S> To perform this test, Tory and Grant would have to eat the same food, drink their alcohol at the same time, and sleep for the same length of time in the warehouse for consistent results. <S> Kari (who could not take part because of her pregnancy) then devised a battery of tests to measure dehydration, memory, light/sound/motion sensitivity, and coordination. <S> Without having drunk alcohol, Tory and Grant performed well on their control test. <S> They then performed the beer test, with Tory drinking 14 cans of beer and Grant drinking six. <S> They both performed significantly worse than the control tests, signifying they were badly hung over. <S> They then repeated the test with a mixture of beer and liquor, making sure to drink an equivalent amount of alcohol as in the first test. <S> The next morning, Tory and Grant improved significantly and felt much better than in the previous test. <S> Thus, the Build Team declared the myth busted. <S> NYTimes also addressed this back in 2006 - http://www.nytimes.com/2006/02/07/health/the-claim-mixing-types-of-alcohol-makes-you-sick.html <S> "The pattern, more often, is that people will have beer and then move on to liquor at the end of the night, and so they think it's the liquor that made them sick," he continued. <S> "But simply mixing the two really has nothing to do with it." <S> In general, the ABV of wine is higher than that of beer, so if you consume a higher ABV after a lower ABV, you will feel its effects faster, but if you're still drinking at the same rate, you won't notice you've had any effect as readily as if you drank at the slower rate more generally associated with the higher ABV beverage. <A> This seems to more myth than fact. <S> I am not finding anything scientific that CO2 causes faster absorption. <S> If that was the case you would see carbonated fitness drinks for faster absorption. <S> There are studies that Champagne go to the head faster <S> but it also has a lot of sugar. <S> The more like causality is people that mix also just plain drink more. <S> For me personally I like a shot (or two) of tequila first to get a buzz and then sip beer. <S> I am more likely to burn (most) of it off by the time I go to bed. <S> If you have a belly full of beer <S> there is just a volume of liquid for the body to process and hard liquor on top is just more liquor. <S> Shots early <S> and you have more immediate and clear feedback <S> you are over drinking. <S> As for wine it has about the same effect on me and the alcohol difference <S> is not that great. <S> I just don't like the taste of mixing them in one evening. <S> There are studies that higher percentage drinks are absorbed faster and it make sense as the body is processing a smaller volume for the alcohol.
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You can get stupid with a few beer and then just get even way more stupid with shots as you are numb and the beer dilutes the alcohol so you don't feel the boom.
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Will temperature changes cause a beer to "skunk" or otherwise spoil? In my fraternity days, there was a constant fear of beer (typically kegged but also bottled) getting "skunked" as a result of warming up and cooling down too many times, possibly even once. Do non-extreme temperature changes such as moving a beer back and forth from a counter to a refrigerator cause perceptible changes to beer? If not, what about more extreme changes, such as sitting in the bed of a truck or a trunk? I'm aware that light has a degrading affect on it's own, so let's assume this beer is in a keg or a light-proof box. <Q> In short, no. <S> As explained by George de Piro , a biochemist and Brewmaster of C. H. Evans Brewing Company— <S> When light hits beer, it provides the energy necessary to drive a reaction that transforms the iso-alpha-acids into 3-methyl-2-butene-1-thiol. <S> The “thiol” part of that somewhat cumbersome name indicates that there is sulfur present. <S> Sulfur compounds often have strong, offensive aromas. <S> Some musteline animals, like skunks, have evolved the ability to produce this chemical, and use it for self-defense. <S> [...] <S> This photochemical reaction is the only cause of skunked beer. <S> Cycling the temperature of beer from warm to cold and back again is also not implicated. <S> Storing beer in the dark is the simple way to prevent skunking. <S> It's actually pretty amazing how quickly this reaction can happen! <S> From the same article, The photochemical reaction that skunks beer occurs very quickly; a well-hopped beer in clear glass can become noticeably offensive with just 30 seconds of exposure to sunshine. <S> To wrap it up, <S> Since light is an essential ingredient in the skunking process, beers packaged in kegs, cans, and opaque bottles cannot be skunked. <S> Here's the most detailed experiment I could find— The Impact of Lightstruck and Stale Character in Beers on their Perceived Quality: A Consumer Study . <A> Slight temperature changes will not spoil your beer. <S> Large temperature changes will. <S> The "skunky" beer is actually lightstruck. <S> This is exactly what it says: the beer has been damaged by light, such as sunlight or florescent light. <S> When UV lights penetrate the glass of a beer bottle, they mess with the chemical makeup of some acids produced by the hops. <S> The result is a new compound called methyl mercaptan, which is one of the components of the defense mechanisms found in the skunk. <S> This is prevented by packaging beer in brown bottles, which is better protected from UV rays. <S> Unfortunately, this lets those green rays get in, which makes sense as to why some beers are served with lime: it keeps away the "skunky" smell for a while. <S> In reality, it doesn't take much to spoil your beer. <S> If your beer in a green or clear bottle has not already been spoiled before it got to the store, about a minute's worth of exposure to the sun would do it. <A> I've hauled everything that comes out of the brewery in Golden, CO. <S> None of it was hauled in a reefer trailer. <S> All in a dry van. <S> Some loads sat in 95 degrees for days before delivery. <S> Just saying. <A> Actually beers from Anheiser Busch have preservatives in them witch it can get warm or cold or whatever. <S> Coors beer products on the other hand do not have preservatives and have to stay cold all the time. <S> I worked for Coors Distributing and we kept the beer cold on the train to the warehouse to the trucks, to the customer. <S> All refrigerated.the whole way. <S> That is all I know that i was told.. <A> I have read a lot on this and keep finding it's a myth. <S> I am a raging alchy and drink beer all the time. <S> I get this bud from Walgreen's and they have a horrible stocking procedure, I know for sure the beer is cold <S> , then they let it get warm, then refridge it <S> (the cans are always sweating). <S> It's been 5 times <S> I've drank this bud from them and all the time my stomach kills me from it. <S> I think it, for some reason, creates more gas (lot of foam in my stomach, feeling like I have to burp, but cannot). <S> I drink the same amount of beer on any given day from a good distributor and have no problems. <S> Side note to add, the beer also has a lemony taste to it, so I don't know exactly the chemical reaction,but I'm positive that going from cold to room temp, then cold again screws the beer. <A> Fluctuating temperatures cause oxygenation of your beverage , but only over one or several years. <S> This may spoil your beer, but not "skunk" it. <S> The same would apply for all alcoholic beverages.
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Warm storage, while damaging to the flavor of beer, does not skunk it. I have read that wine in wine cellars at around 14-16 degrees celsius last the longest, and that unstable and fluctuating temperatures over many years will spoil your wine by oxygenation.
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Does chocolate stout contain real chocolate? Various microbreweries make chocolate stout that does indeed, to varying degrees, taste of chocolate. Does it really contain chocolate, and how is chocolate used in the brewing process? <Q> It depends on the brew really; some do and others do not. <S> More often than not, the chocolate flavor comes from the techniques used to roast the malts rather than chocolate itself. <S> Some brewers will add additional chocolate to enhance the chocolate flavor a bit, but it generally doesn't get its flavor primarily from the chocolate. <S> The same is true for coffee stouts. <S> As a side note, I've recently tried a smoked imperial IPA (Runaway Smoked Ferry Imperial IPA) from the Port Jeff Brewing Company, a local microbrewery. <S> I swear to God, it tasted like bacon! <S> But there was not an ounce of bacon in it as confirmed by the brewmaster. <A> Yes. <S> Typically chocolate stout does contain chocolate. <S> I've typically added chocolate to my home-brew during the boil phase (since it adds more sugars <S> and I want the chocolate to melt). <A> That very much depends on the brewery. <S> These happen to add a fair amount of chocolate and coffee characteristics to the final product.
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Some use cocoa nibs to add the chocolate flavor, but often they use what are called "chocolate malt", grain that is roasted until it's the color of chocolate.
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How much of an impact does the water have on a beer? How much of an impact does the water (minerals/quality/distilled) have on a beer? <Q> Most of beer is water, so it is vitally important. <S> Here in Atlanta, we have some of the better tap water compared to many cities, but Monday Night Brewing in particular takes all minerals and chemicals out of the water and adds back in the appropriate properties to match the style of beer that they are trying to brew. <S> They emulate the water from the origin of the beer style. <S> Just consider that anything but the most pure form of water will impart some taste in your beer good or bad and is worth being aware of. <A> Water is extremely important. <S> When touring Brooklyn Brewery, the brewers went on and on about how great it is for them to have access to the NYC water supply. <A> It's important enough that many British brewers modify the composition of their water to more closely mimic the mineral content of water drawn from wells near Burton upon Trent , where traditional styles are considered to originate from. <S> This process is called Burtonisation . <S> I've noticed for my part that some traditional bitters I've drunk have had a noticeable and not entirely pleasant aroma somewhat like old eggs, which I would guess is the sulphur content that is added in this process. <S> I don't particularly care for beers that taste like this, but each to their own. <A> Beer might be completely undrinkable if the water is poor quality. <S> Usually it is ok to use your own tap water, but if it is softened, you'll want to buy bottled water, as the added sodium from the softener will ruin your beer. <S> I personally use purchased water from the grocery store. <S> Usually 50% distilled, 50% "spring". <S> Though honestly it's probably all tap water from somewhere else.
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During brewing, the quality of the water is important because the minerals can affect a beer recipe greatly.
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What's the difference between an "export" beer and a regular beer from the same brewer? In the UK at least, a great many beers are marketed with a regular version and a fancier (more expensive) 'export' version. For example: Carlsberg and Carlsberg 'Export'. Is there any reason why the imported beer might be reasonably different (such as the legality of certain brewing methods outside of the UK) or is this just marketing fluff? <Q> It's about as meaningful as the fact that several dozen breweries have a beer they label as "Select". <S> One common usage is for a line with slightly higher ABV (it keeps better in shipment!) or tailored to suit the ABC laws of other jurisdictions to which it might be shipped. <S> But there isn't any single meaning that's widely understood. <A> When I visited Stella Artois brewery in Leuven (Belgium), they told us that they distributed the same beer in two kind of bottles. <S> In brown reusable simply labeled bottles for distribution inside Belgium (note that it is a regular beer, the most drunk in Belgium), and in green more fancier labeled bottles with "imported" insciption on it for distribution around the world. <S> In belgium Stella Artois is a normal cheap beer, but where I live, in Spain, it is sold as imported special beer and costs more than double. <S> However, the liquid inside the bottles is the same. <S> So it is just marketing strategy. <S> The guy who showed us the brewery was clear. <S> While people outside belgium are kind to pay more for a fancier bottle, they would distribute more expensive fancier bottles. <A> While I was in Germany, you had pretty much two common choices of beer available from the local brewery: Pils and Export. <S> They were quite different, with Pils being lighter in color and taste and Export being darker and a little heavier flavor. <S> They were in the same colored glass bottle with different labels. <S> The name had nothing to do with whether it went out of the country or not. <S> Now, maybe back when it was first developed way back when, it was exported to another people somewhere, I don't know. <S> My beer knowledge is not that impressive, so I have relayed what I experienced.
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They are obviously two different beers. It doesn't actually mean anything; or at least, it almost never means the same thing twice, and doesn't refer to any specific common style or process. For example, in the case of Molson Export, the story goes that it was deemed so high quality that it was "good enough to send overseas" - and, implicitly, better than competing imported brands.
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Why does Guinness have a special pouring process / bottle, while other stouts do not? Guinness is sold in bottles and cans with special nitrogen widgets; the taps are specially rigged to have a two-step pouring process; heck, there's even a certificate given to people who learn how to "pour the perfect pint" at the Guinness factory in Dublin. My question is: what makes Guinness so special? Why aren't these tactics used by other stout (or similar variants) producers? <Q> Guinness is "carbonated" with nitrogen, where most beers use carbon dioxide. <S> This requires different hardware, bottling equipment, etc. <S> If you've ever witnessed the appearance of a perfectly poured Guinness, and paid more than $5 USD for it, you'll understand why. <S> It's partly about presentation. <S> As one of the oldest beers on the market, it requires us to jump through some hoops to ensure we are enjoying it correctly. <S> In short: I think it's mostly marketing! <A> Guinness, and a few other beers out there, are carbonated in part with nitrogen, which has much smaller bubbles. <S> This creates a smoother mouthfeel; this is the "creaminess" that is often described. <S> The use of nitrogen is probably uncommon for a few reasons. <S> Firstly, there's the added production cost in the bottled or canned product: the widget. <S> Secondly, I would wager that most breweries want the product to taste similar on draught as in a can or bottle, and it's very uncommon to have nitrogen available in a taproom. <S> (You can get special taps <S> which "cream" the beer on the way out, but again, for consistency those would have to be installed where-ever you sell your beer.) <S> So it's something of an uphill battle. <S> Finally, not all beers may benefit from a different type of carbonation than what's prevalent... <S> but of course, that's subjective. <A> While, as object88 says, it is uncommon for draught beers to use nitrogen, it is becoming more prevalent, though certainly not dwarfing CO2 draught beers anytime soon! <S> So, it is certainly possible to remain consistent from bottle to draught, though it is less common and more costly to do so. <S> This is more common with malty beers, say stouts and porters, than it is for hoppy beers. <S> The nitrogen makes smaller bubbles than CO2, and creates a thick head due to the lower solubility of nitrogen in water than CO2 at the same temperatures. <S> This creates the thicker mouthfeel that Guinness (as well as other nitrogenated stouts) are known for. <S> CO2 will likely continue to be used for most hop-forward beers, since it pushes more aroma out of the beer (including the delicious hop scent!) <S> while nitro is more about the mouthfeel and well-rounded flavor. <S> A few reasons why other beers don't use the small nitrogen ball devices ("nitrogen widgets"): Alcohol laws (or FDA or something?) doesn’t allow craft brewers to add widgets/foreign objects to alcohol (cans). <S> Imports exempt? <S> [ Source ]
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Both bottled and draught beers use nitrogen to add bubbles instead of CO2 on occasion. Not cost effective for small brewers, who are only just able to start affording canning systems.
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Should I get beer in bottles or in cans? Sometimes, companies offer the same beer in bottles and in cans. Everything else being equal, should I go for the bottle or the can? I know that e.g. Guinness have their "floating widget" in their cans that releases nitrogen when you open it, but assume that this isn't the case. In particular, I'm looking for the effects the inner coating/material of cans has on beer. <Q> A modern canned beer should never taste like metal. <S> If it does, you're probably drinking straight from the can, and while the folks at The Alchemist might recommend that , I can't say I share their view. <S> Modern beer cans are lined with a water-based chemical that essentially ensures that your beer never touches metal. <S> This in turn means that strictly speaking, canned beers will keep longer without being skunked , and pressurized packing means there's less air in a can then a bottle, which adds further preservative benefits. <S> That said, very few beers that are good enough for this decision to matter are offered in a choice of containers - most small breweries just don't have the capacity to both can and bottle - especially of the sort of small-batch stuff that you'd actually be interested in trying to cellar and age. <S> Furthermore, there are significant environmental and economic arguments in favor of both bottles and cans. <S> At the end of the day, choose the packaging that's more convenient for you to store, consume from, and recycle when you're done. <S> The quality difference is essentially insignificant. <A> As you might expect, cans can impart a metallic flavor on some beer, but on the flip-side, they are much less prone to skunking. <S> So if you're looking to store the beer for a while in a cool, dark place, I'd say bottle. <A> I'd strongly dissuade anyone from ever drinking anything from an aluminum can, not just beer. <S> That chemical, however, is Bisphenol A which is a potentially very dangerous chemical compound for your body when ingested... <S> CDC still says the chemical's health effects are unclear, research on chronic exposure has linked it to high blood pressure and heart rate issues. <S> https://www.usatoday.com/story/news/nation/2014/12/14/bottle-chemical-bpa-health-newser/20397547/ <S> Depending on who you ask, one will get a variety of answers: ... <S> has also become associated with a range of ailments, including cancer, reproductive trouble, and irregular brain development in kids. <S> BPA is well established as an endocrine-disrupting chemical, meaning that it likely causes hormonal damage at extremely low levels. <S> The question is whether we get enough of it in beer (and other canned goods) to cause harm. <S> https://www.motherjones.com/food/2015/02/no-i-cant-why-im-turning-away-canned-craft-beer/ <S> And this: BPA, in small doses, has been linked to obesity, early onset of puberty, diabetes, heart disease, reduced penis size, growth of male breasts, and even mean girls. <S> https://www.treehugger.com/health/who-cares-about-bpa-canned-beer-more-popular-ever.html <S> Also, let's hope that it is true that this compound prevents leaching of aluminum into beer considering <S> aluminum is one of the most toxic heavy metals for the human body. <S> That said, if you don't really care about a little thing called "Your Health," then there are several pragmatic reasons for why aluminum is good for beer storage: 1.)Aluminum blocks light and oxygen from entering the beer itself <S> 2.)Cans are generally lighter and smaller than bottles, making them easier to carry and store 3.)Cans can allow beer to become colder more quickly https://learn.kegerator.com/beer-cans/ <S> While the argument that beer spoils more quickly in bottles is accurate, who is letting the beer sit around long enough for that to happen?? <S> Not I... <S> Also, while cans become colder quicker, they also become warmer more quickly when exposed to heat. <S> Whereas, bottles will remain colder for much longer... <S> some folks say it tastes like metal, some don't. <S> This debate is non-existant when drinking from bottles, however... With Guinness in particular, I always prefer the taste from bottle over that of the can... <S> so in conclusion, ymmv but make it a bottle for me.
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As mentioned by LessPop_MoreFizz, beer cans are lined with a compound that attempts to prevent contact with the aluminum... However, if you plan on keeping it in a light place or outdoors, a can is probably your best bet. Finally, the taste issue - minimal research in your favorite search engine will show you that it is a 50/50 debate...
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How is gluten-free beer made? I have a friend who is Celiac and can only drink gluten-free beer. How on earth is it made? <Q> These beers are made with non-gluten containing grains such as millet, rice, corn, or buckwheat as opposed to glutenous grains like rye, barley, or wheat. <S> As a side note, I recommend your friend give Omission Beer a try. <S> I had it once on accident at a social event. <S> I couldn't tell the difference between it and the real thing until I got home and looked it up online. <A> Incidentally, this also means that cheap macrobrews such as Coors and Budweiser, which are often brewed with the cheapest of cheap adjuncts in their grain bills (such as corn and rice) end up being gluten-free (or very low gluten, legal definitions of the term vary) as well. <S> Because the legal definition of 'gluten free' in many jurisdictions allows for very low quantities of gluten (generally less than 20 ppm), many gluten free beers include small quantities of rye malt for flavoring purposes. <S> While some individual with celiac are able to tolerate these low levels of gluten (as are non-celiacs pursuing a gluten free diet for other reasons), tolerance can vary, so be careful when selecting a gluten free beer, and be aware that they can vary wildly, both in quality, and in gluten content. <A> Some Gluten Free beers actually have gluten at the moment they are made, for example in the case of Omission <S> the beer goes trough a proprietary "gluten removal process" and then they use a gluten test called the Competitive R5 ELISA, which is used to test foods that are "hydrolyzed," or broken down. <S> This test looks for a specific lengthy fragment of the gluten protein and returns a negative result if it doesn't finds it. <S> If the test results are under 20 parts per million (as @LessPop_MoreFizz's answer says), then it can be called "gluten free" in the USA... <S> and yes, I've heard people with serious celiac disease can still "feel" that concentrations and get sick. <S> "Estrella Damm Daura" on the other hand has only 3 parts per million, they also have a proprietary process to remove gluten. <S> Estrella Damm Daura is an European beer made in Spain, obviously in <S> Europe health and food standards are way better than USA's. <S> In Europe, food authorities will never allow a brewery to call a beer with 20 ppm "gluten free". <S> Just don't confuse it with "Estrella Damm" which is their regular beer. <A> Just to add to this topic, I think it's important that the correct terminology is used since a number of answers contain false information. <S> In the beer world, "gluten free" can only be used if the ingredients used to brew the beer do not contain gluten. <S> Sorghum appears to be the most popular ingredient for making GF beers, but there are a number of other options including buckwheat, millet, honey, even chestnuts. <S> Redbridge is an example of a GF beer. <S> I have yet to taste a GF beer that I enjoyed as sorghum specifically gives off a cider-y flavor and all the beers end up thin. <S> There are also beers that are brewed with traditional ingredients that contain gluten, but an enzyme called Brewer's Clarex is added to primary fermentation. <S> Clarex was originally used to clear beer and prevent chill haze, but it was discovered it also breaks down gluten such that, when tested with traditional gluten tests (ELISA), the beer is well within the "gluten free" threshold (<20 ppm). <S> These beers cannot be called "gluten free", though, rather they can only be labeled "crafted to remove gluten". <S> Omission brews "gluten reduced" beer (which are very good IMO), but apparently Yards also uses Clarex in some of their beers (even though they don't label their beer as "crafted to reduce gluten").
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In general, such beers are made with grains that contain little or no gluten, such as buckwheat, sorghum, rice, or corn.
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What's the best way to store beer while camping in hot climates? Every August I go camping 1 for a week or two in western PA, and I like to take along some beer to drink in the evenings. What I've been doing, to save cooler space (and reduce the amount of ice I have to replace each day), is to keep most of it out and just keep a buffer of a couple bottles in the cooler. But this question makes me wonder whether that harms the taste, because while I can control for light I can't do much about storage temperature. Should I just suck it up and put everything on ice when I get there? I haven't noticed a problem so far, but I tend to take a variety of beers (I don't drink the same thing every day) so I might never notice on my own. 1 This is not primitive camping with tiny, heat-absorbing nylon tents. Most of our tents/pavillions are canvas, and we have a small cabin available. No electricity is available, however. <Q> I use 3 methods to store the beer, and others, while camping: <S> Cooler: <S> The way you mentioned in your question. <S> Sunk in water: If possible, put the beer either in a plastic bag or in a hole in a nearby water body, creek or river. <S> Second and third possibilities will keep it cool, but not really cold, depending on the area. <S> The you can cool it even more by placing it in ice shortly before consuming it. <A> Temperature does not skunk beer, contrary to popular belief. <S> It is much more important to keep it out of the light. <A> Using a 12% salt brine ice slurry in your esky (cooler). <S> The salt allows the water to "superchill" without freezing. <A> A couple at time does not reduce the amount of ice you need to replace. <S> The cooler has the same insulation and same surface area. <S> It will have the same heat loss. <S> Why put it on ice when you get there? <S> Top off the cooler at the last store. <S> I suggest a separate cooler for drinks as you are in and out of it more. <S> If ice runs out nothing will spoil. <S> As for food you can get a week in a good cooler. <S> Pack as many foods frozen as possible. <S> Open and close as few a times as possible.
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Pack the cooler before you leave and ice it down. In the ground: Dig a hole in the ground in a shady area and store it in there.
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How does serving temperature affect the taste of beers? For example, from the label of Uinta's Crooked Line Labyrinth Black Ale: Flavors are enhanced when served cool, not frigid. How does serving temperature affect the taste of beers? By "How?" I'm asking more about its effects on flavor, e.g. hoppiness, crispness, the aftertaste, etc. more so than the chemical process. * That is, what flavors become pronounced or dulled with the changing of temperature? There's a question, What temperature should I serve my beer? , where an answerer states, for example, that letting darker beers warm up brings out new flavors—but what flavors? It doesn't seem to be the case that cooling kills all desirable flavors in general—for example for pilsners, lagers, and hefeweizens, "letting them get warm changes their flavor profile for the worse" (from the same answer). * Knowing the chemical process, e.g. how certain elements or ingredients react or suspend differently according to temperature, would be very interesting indeed, but it seems difficult to find solid literature / knowledge on the subject. <Q> There is a blog post which also cites this article discussing the chemical effects of cooling and dilution on whiskey. <S> The post concluded that the mix of dilution and cooling causes the alcohol to become soluble, which releases the flavour. <S> Ethanol becomes more soluble when whiskey is diluted and cooled, this promotes release of flavour molecules <S> I think this theory is applicable to beer, but with a few caveats; firstly, beer is already diluted and doesn't need any more water added; secondly, the alcohol content of beer is much lower than that of whiskey, so not as much cooling would be required. <A> There are a few components to the interaction between flavor and temperature, but one key one is simply that cold numbs your tongue . <S> At least, extreme cold ( e.g. "cold as the rockies"). <A> wow. " <S> cold numbs your tongue. <S> " Seems like a very unusual answer to a sensible question. <S> I can say that each time I try different types of ale or beer <S> I like to read the label for their opinion but most of the time I start with fully chilled and pour some in a glass and let it settle down then take a sip and wait for maybe 5 minutes and try another and so on until I get an opinion of how that particular brew changes and then read their opinion (if one exists) again to see if my experience agrees or to compare what they must be trying to focus on based on their opinion. <S> Once I figure it out then that is how I drink that brew. <S> Although I accidentally poured some Chimay Grand Reserve blue label and forgot it one night. <S> When I returned maybe an hour later, it was fairly room temperature. <S> The amazing thing is that it smelled fruity like a wine and even had a wine like taste. <S> I use a wide wine glass for my sampling <S> so it captured some of the vapors probably better than a mug or a bottle <S> would have. <S> I do not always have an hour to wait to let that happen <S> but it was a pleasant surprise. <S> Usually with the Chimay <S> I let the massive head settle down then <S> take a sip because at cold temp it has one characteristic that I like. <S> Then I wait for maybe close to 10 minutes and drink some more. <S> Typically between 10 and 20 minutes is the part I probably like most for general drinking. <S> Right after it starts warming up from frige temp it begins to seem too much like drinking alcohol. <S> I can feel and taste the alcohol <S> then it gets a little warmer and begins to take on a sweeter malty flavor. <S> Then allowed to sit longer it goes into a less attractive taste only to eventually seem like wine after it makes it to another level of warmness. <S> Sometimes I pour a 2nd glass after the first reaches a certain flavor and sort of alternate between them to enjoy the different flavors that all came out of the same bottle.
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As such, overly cold beer will dull any strong flavor (hoppiness, bitterness, etc) and hide weaker ones.
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What is the highest alcohol content achievable through brewing? What is the highest level of alcohol you can achieve when brewing beer naturally, without adding alcohol? I know that many strong, popular beers (~10% alcohol) are simply mixed with alcohol, but what level of alcohol can be achieved in natural brewing process? <Q> That depends on what you mean by "naturally". <S> There are some strains, such as the "Super High Gravity Ale Yeast" by WyLabs, which can handle up to 25%. <S> But there are techniques, such as freezing the beer to create a more concentrated product, which have been used to get up to 60+%. <S> In this case, alcohol is not added , but rather, water is removed , altering your ABV. <A> The reason there's a limit is once the alcohol content is too high, it kills the yeast, so fermentation stops and no more alcohol is produced. <S> EDIT: <S> The Wikipedia page on yeast in winemaking has some details on when different types of yeasts die out. <A> I am taking this from a website cited at the bottom. <S> Popsci has a LOT of cool beer articles. <S> Fractional freezing -- "jacking" in old parlance -- has a long history in the United States. <S> The beverage applejack was produced using this method by first fermenting apple juice into hard apple cider. <S> Then barrels of this cider were left outside during the winter and the connoisseur would occasionally fish out the frozen chunks of water, leaving an ever-concentrated batch of hard alcohol behind. <S> At some point in the 20-25 percent ABV range, the liquor would stop freezing at ambient temperatures and the booze was ready to consume as "Jersey Lightning. <S> " It was also used as currency. <S> Moving into the malt-beverage world, brewers in Germany use fractional freezing to make eisbock. <S> These brews are usually just regular bock beers, which clock in at 6 percent ABV, freeze-concentrated to something in the 13 percent ABV range. <S> Frankly, there are probably easier ways to get high-proof beers (make a barleywine, for example) than by starting with a mid-strength one and concentrating it, but there's a market for eisbocks and it's possible to find them in the US as well. <S> A more infamous set of freeze-concentrated beers was made by the Scottish brewery BrewDog in their quest to make "the strongest beer in the world. <S> " The first was Tactical Nuclear Penguin, a beer that started with an ABV in the teens and ended at 32 percent ABV. <S> Then a little brewing war started up between BrewDog and German brewery Schorschbräu to make ever-stronger beers. <S> Schorschbräu made a Schorschbock at 40 percent ABV, BrewDog countered with Sink the Bismarck at 41 percent ABV. <S> Then came another beer at 55 percent ABV (that's 110 proof, my friends). <S> Schorschbräu is current record-holder with Schorschbock 57, at 57 percent ABV. <S> Article <A> Note that Ann Hagen ("Anglo-Saxon Food and Drink") argued that the strongest naturally brewed drinks available in Anglo-Saxon times were probably strongly brewed meads at least 20% abv. <S> Her basis is in discussions of specific gravity of the resulting beverages in historical records. <S> I think it is likely close to that <S> and no more because I see other reasons to wonder if specific gravity could have been reduced by other additives (in particular henbane). <S> I love studying history. <S> It is useful in so many fields! <S> In general getting much above 10-15%abv requires specialty yeasts or concentration techniques, and getting much above 20% is going to require some sort of concentration. <S> I have however seen cases where these rules go out the window in wine making experiments (a friend of mine accidently brewed a mango wine with 22% abv using standard wine yeasts, which surprised us both). <A> There is a beer called "Snake Venom", by "Brewmeister" a scottish brewery. <S> The alcohol content is 67.5% . <S> It has been verified by Trading Standards and is officially named the world´s strongest beer. <S> The wiki entry states that they use the process of fractional freezing to achieve such a high percentage of alcohol. <A> 28% ABV is the best I have managed with my yeast though it needs plenty of sugar added to whatever you are brewing apart from mead. <S> Getting the yeast from the boot's from it's original 8% to 20% took 8 years getting it from 20% to 28% has taken 25 year's <S> and I haven't been able to get any increase on that 28% in the last 5 years though it is getting more consistent & given enough sugar it rarely dips below 28%. <S> Ignore any references to Brewmeister here there <S> "cold brewing" process is Fractional freezing more conmanly called Freeze distillation where they remove water by freezing it out <S> this has nothing to do with the brewing process. <A> I just finished a batch of Applejack. <S> After freeze distillation, I obtained a 19% ABV, however the yeast kicked back on STRONGLY after it warmed up again. <S> I had to boil it to kill the fermentation. <S> Different yeasts can handle different ABV before being killed off by the alcohol. <S> I used Lavlin EC-118. <S> For your yeast it may differ.
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I think it's generally around 15% alcohol by volume, but the exact amount will depend on the type of yeast. Fractional freezing is the best way to increase the alcohol content of beer.
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What's a good beer to go with lasagna? What beer sort would pair good with lasagna, and other sorts of food with high tomato content? What makes the taste of that beer compose good with the taste of lasagna/tomatoes? <Q> Thinking about a tomato pasta, I get acids, strong aromas, and a lingering mouthfeel. <S> Based on this, I would lean towards a Flanders Red or Flanders Brown / Oud Bruin , depending on the acidity of the sauce (the red for more acid, the brown for less). <S> These beers tends toward a wine-like experience, with their own acids and richness. <S> You won't have a lot of hop presence, which would battle the aromas of the food, and the sour characters of a Flanders Red would compliment a strong tomato sauce. <S> Alternately, perhaps a English-style brown ale , for its low bitterness and malt profile. <A> Previous answers are good, I'd just add to pay attention to ABV, which is gonna be mid-high (around 6-7).As <S> suggested here <S> , you'd want the alcohol and the (not too much) hop to cleanse your palate, and it is maybe "easier" than the acid of sour ales or Oud Bruins. <S> Such opulence (...) goes well with a well structured craft beer, but with sharp "weapons" to de-grease the palate. <S> I would suggest an amber ale, or a darker amber: caramel malts, lightly toasted - excessive roasting may in fact have to battle with ingredients such as tomatoes. <S> (...) <S> But absolutely shouldn't be too sweet. <S> So we'd prefer a product that is dry, bitter and strong with good carbonation, since bubbles help the drinkability. <S> As for the alcohol, it would be preferable not to exceed 6 and 7 percent <A> As object88 mentioned, you're gonna want a Flanders Red or Flanders Brown because they are more wine like than beer like. <S> You're gonna want to avoid overly hoppy beers like your IPA's or even pale ales. <S> You could probably get away with a good lager or pilsner as well. <S> Another suggestion, if you can get your hands on it would be one of Dogfish Head's newest ancient ales, Birra Etrusca Bronze , which is a recreation of an ancient Roman beer from the Tuscan part of Italy.
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Our beer, we said, must also have the ability to " clean up" the palate, perhaps with a touch of citrus fruit or herbal, with a pleasant feeling of hops.
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How do popular Polish beers fit into the "periodic table of beers"? In Poland, outside of imports, microbreweries, and various less popular varieties, about all mainstream brands come in two classes: Piwo Jasne ('light beer') Piwo Mocne ('strong beer') The two comprise the massive bulk of the market and are about never labeled differently, save for brand-specific marketing variations. I'd like to learn how they fit into the wider image. Are they lagers, stouts, ales, or maybe something yet different? A class of their own? <Q> Piwo Jasne is, translated, "light beer". <S> It's the common market name for all 'light' beers, and they are mostly pilsners. <S> They are dark, as the name suggests, and usually quite sweet. <S> Piwo Mocne - this is simply the beer that is more condensed, so it has more alcohol. <S> That can be light beers or dark beers (for example, very good dark strong beer "Warka Strong"). <S> Those names are the most popular market classifications in Poland, but usually you'll find more details on label or producer's page. <S> For example, many beers have information, that they are pilsner-type beers. <A> In my (somewhat minimal) experience, Piwo Jasne and Piwo Mocne are both most commonly pilsners or perhaps more generally pale lagers. <S> Piwo Mocne is higher in alcohol content and might be called a "strong pale lager", or perhaps tagged with the modifier "Imperial" to indicate the increased alcohol. <S> That said, I don't think there is anything inherent in the term that precludes, for example, a strong ale being sold as Piwo Mocne. <S> The two terms in the question aren't prescriptive of specific style. <A> Given how much modern Polish beer has in common with <S> mass-market German and Czech beer- combined with a small handful that I've tried here in Germany- <S> they're what one would call "European pale lagers" or "International pilsners," depending on what book or site's style names you're going off of. <S> In response to a previous answer, color has nothing to do with ale v. lager, nor alcohol concentration (Guinness is an ale and 4.2% where Aventinus Eisbock is a lager and 12%), it only tells you how it was fermented. <S> There are tons of dark lagers around: <S> Schwarzbier, Munich dunkel, Rauchbier, Doppelbock, the aforementioned Baltic porter, and the Czech 14* and 18* dark lagers. <S> I or someone will need to look more into this, but those terms might be bureaucratic in nature- up until the 90s, Germany had multiple beer categories based on the beer's original gravity that determined how it would be taxed and sold, <S> sort of like how Texas used to label everything above a certain ABV% "ale". <S> TABC Changes What it Means to Be a Beer.
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Piwo Ciemne - this is "dark beer", so something like ale.
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Does beer really go bad after the 'best before'-date? Does beer really go bad after the 'best before'-date? I hear I can drink beer even after the expiration date, but is it safe and does it still taste good? <Q> The beer will not be bad in the sense of unsafe to drink, since no harmful pathogens grow once the beer is fully fermented. <S> So you can certainly drink the beer. <S> However, the beer may not taste good! <S> Over time, the beer will oxidize, both from oxygen introduced during packaging, but also through the release of oxygen from compounds previously oxidized in the beer. <S> The oxygen causes the beer to stale, producing tones of sherry, paper, cardboard. <S> Hop aromas are muted, and hop beta acids oxidize to produce an unrefined bitterness. <S> Other forms of staling can lead to a soap taste. <S> Generally, the higher the alcohol content of the beer <S> the less you need to be concerned with the use by date. <A> StillTasty.com has the following to say with regards to beer - particularly specifying that this applies to regular or light beer from bottles or cans manufactured by major breweries: Opened Containers Good for 1 day, refrigerated. <S> Tips: <S> Keep refrigerated and tightly covered. <S> After opening, most commercially manufactured beer will remain safe to consume if properly stored, but it will quickly become flat and lose flavor. <S> Unopened Containers <S> Good for 4-6 months, in pantry or refrigerator. <S> Tips: <S> The precise answer to the question "How long does beer last?" depends to a large extent on storage conditions - store beer in cool, dark area. <S> Keep beer away from direct sources of heat or light; too much exposure to light can cause beer to develop a foul taste. <S> To maximize the shelf life of beer, store beer at a temperature between 45° F and 55 <S> ° F (colder than the typical room temperature, but warmer than a refrigerator) <S> - if this is not possible, store beer in the refrigerator. <S> How to tell if beer is bad? <S> If beer develops an off odor, flavor or appearance, it should be discarded for quality purposes. <S> "Best By," "Best if Used By," and "Use By" dates on commercially packaged foods sold in the United States represent the manufacturer's estimate of how long the product will remain at peak quality - in most cases, the beer will still be safe to consume after that date, as long as it has been stored properly and the package is not damaged. <S> Beer made by some micro-breweries may not retain peak quality as long as beer from major breweries. <A> This depends entirely on the beer. <S> As a rule of thumb I would say that any beer which is re-fermented once bottled, can be preserved for several years. <S> You need to be careful when preserving, but it's not unheard of to drink 35 year old beers. <S> Often these beers are the darker, stronger ones like Westmalle or Orval. <A> This depends on many factors, but usually best-before date is what is states, also the date before which the full quality of the product is guaranteed. <S> It doesn't mean you can't consume it afterwards, it just means that you can't make formal complaint about the taste or potential sickness caused by consumption of the product after that date. <S> The people from food industry said me, that it is general rule, <S> that <S> the best-before date is normally exaggerated in bottom direction, just to protect the company from potential sues. <S> I've often drank beer much after best-before date, and as long as that date wasn't exceeded by more than a year, I haven't noticed any big difference in taste. <A> It should still be safe, taste good is a personal opinion. <S> Some beers age <S> well, high alcohol, sours, and smoke beers. <S> Others don't age as well (hoppy beers). <S> Plus it all depends on how the beer was stored. <S> Out in a hot garage? <S> Sitting in your window sill?
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Storage times shown are for best quality only - after that, the beer's color or flavor may change, but in most cases, it will still be safe to consume if it has been stored properly.
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What is being doubled or tripled in a doublebock/triple bock? Some beers are classed as "doublebock" and some as "triple bock". Doubles seem to be a little stronger (higher APV) than average and triples seem to be stronger than that, but is that they definition or an effect ? What exactly is being doubled or tripled in the production of these beers, and is the primary goal strength or some aspect of flavor or something else? <Q> Doppelbock (or double bock) is intense in its maltiness and higher than "single" bock in terms of alcohol content, typically starting around 6-7% and going up to around 13%. <S> There isn't anything specifically doubled or tripled; rather, <S> doppel idiomatically refers to be being "bigger"/stronger than a standard bock. <S> In terms of how higher "maltiness" is accomplished, that would depend on the specific beer; mashing at high temperatures, reducing lautering, using certain grains or different yeasts, and other factors all can increase the maltiness of the final product. <S> As an aside, doppelbocks are an evolution of strong monastic brews used as "liquid bread" for fasting monks, as they were not allowed to consume solid food. <S> These sweet, malty beers evolved over time into the modern doppelbock. <A> Typically, it seems people expect single, double and triple to mean higher alcohol content. <S> But that is not exactly true. <S> You have single and double bocks with the same alcohol content. <S> Take Weihensthephaner for example (a respected 1000-year old monastic brewery) <S> : Weihenstephaner Korbinian is a double with 7.4% ABV. <S> Weihenstephaner Vitus is a single bock with a higher ABV of 7.7%. <S> In this case, the single has a higher ABV than the double. <S> More grains and more sugar do not equal more alcohol. <S> The strain of yeast and temperature determine the survivability. <S> Some yeast can live at high alcohol levels. <S> You can feed them all the sugar and grains and they will still die and stop fermentation (producing alcohol) when the alcohol level 'limit' is reached. <S> The eisbock gets a higher ABV by freezing the beer and removing ice. <S> This removal of water is how the alcohol content is increased. <S> Again, most yeast cannot reach 12% (which one typically finds in an eisbock). <S> The single, double, triple label has to do with the strength of the beer overall, including nutrition (calories) and taste. <S> Remember, these 'doppels' were created for sustenance. <S> Careful with the word 'stronger' when talking about bocks. <S> It can mean more malty, darker, fuller, not just higher alcohol level. <A> Ale Le Coq in Sweden make a triple Bock label has rams head with red glowing eyes <S> Mostly Alkies drink it because of the strength <S> but it tastes lovely.
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A triple bock would just be a naming convention emphasizing even further the maltiness and alcoholic strength of the brew.
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Why should beer be kept in the fridge? Beer is usually found in fridges in shops and supermarkets. At home, you would store it in the fridge as well before drinking. On the other hand, many liquor shops have stacks of beer cans outside fridges, and beer in kegs isn't usually refrigerated when it's transported. What are the benefits of keeping beer refrigerated? Which kinds of beer should/must be refrigerated and which ones don't need to be? <Q> Beer should be chilled to the proper serving temperature, which may vary according to ingredients and brewing methods, and even most of those are not set in stone, but can also vary according to taste. <S> Guinness, for example, has a specific serving temperature related to how it was traditionally stored in Ireland (Kegs in the "cold" room, which was often just a room carved out of the hill behind the pub or similar). <S> As far a why grocery and convenience stores keep it chilled, it's basically appealing to the "grab and go" drinker, who intends on consuming it in the very near future, or with a short transport. <S> Often they are slightly higher price than if you were to go to a liquor store. <S> Liquor stores have much larger selection and inventory, and refrigerating everything would be cost prohibitive. <S> The price is generally slightly less than the grab and go locations, although many liqour stores still keep some of the more popular and mainstream beers in the cooler as well. <S> For most commercially available beers, you can cool, warm and recool several times with minimal to no changes to taste. <S> Some craft and/or home brews may be affected more by this process, but I don't know if there is any kind of a list available. <A> Heat and light are the enemies of beer. <S> If you have a "bottle conditioned" beer -- that is, one in which live yeast are still present -- then under warmer conditions, you potentially have active yeast. <S> To some extent, this may just increase the carbonation and alcohol content. <S> However, if most of the fermentable sugars have already been fermented (that is, converted to CO2 and alcohol), the yeast will start "eating" each other, which will result in some very "off" flavors (though nothing toxic). <S> Under cooler conditions, the yeast will be only minimally active. <S> Regardless of whether your beer is "bottle conditioned" or not, the hop acids present from the brewing process don't respond favorably to heat or light. <S> In particular, light can cause them to turn "skunky", which is why Corona -- with their clear glass bottles -- often tastes "skunky". <S> Don't trust a beer in a clear bottle ... seriously. <S> Keep it cool; keep it dark; keep it upright (unlike wine). <A> To quote Strongbad , "A one that is not cold, is scarcely a one at all." <S> In supermarkets you will often see the same beers stored in refrigerated and non-refrigerated sections. <S> Or you may be able to get a beer cold somewhere but only warm somewhere else. <S> If you go to a large beer store you will see beer of every variety sitting in aisles. <S> The general reason for keeping beer on ice in a store is so it can be drunk right away. <S> The one exception I can think of is bottle-conditioned beer. <S> Beer where some degree of fermentation occurs in the bottle, giving it both natural carbonation and causing the flavor to develop over time. <S> You will typically only see bottle conditioned beer as a product of home brewing. <A> When talking about the temperature to store/serve beer <S> it is important to note that there is a difference between types of beer (and what we call beer in the UK and what people call beer in other countries!). <S> The Cask Marque website has a simple page denoting the various temperatures that some types of beer/ale should be stored at. <S> It is important to note that some beers also need to be stored upright to ensure any live sediment stays at the bottom of the bottle. <A> Every beer has a shelf life. <S> Beer will certainly "last" longer if refrigerated. <S> That is, the flavor will evolve more slowly over time at lower temperatures. <S> Storage at higher than room temperature will invite a turning of the beer's flavor for the worse. <S> In some cases, an aged beer might be considered to have an appealing taste, but still refrigeration will slow the aging process and allow the beer to be kept longer. <S> Additionally, the flavor of highly hopped beers will degrade fairly quickly (within several months) at room temperature, and most people would agree that very hoppy beers in particular should be refrigerated because of this.
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The flavors the beer will take on during conditioning vary based on warm or cold conditioning, and the beer will have a more limited shelf life.
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How does boil time directly affect ABV% & IBU? Dogfish Head makes IPAs called "60 Minute", "90 Minute", and "120 Minute". According to Wikipedia : Their names refer to the length of the boil time of the wort in which the hops are continuously added. There is also a limited edition "75 Minute" which is really a blend of the 60 & 90 varieties. What I find odd however, is that these numbers also roughly correspond to the beers' ABV% & IBU. Again, from Wikipedia : 60 Minute: 6.0% ABV, 60 IBU 90 Minute: 9.0% ABV, 90 IBU 120 Minute: 18% ABV, 120 IBU 75 Minute: 7.5% ABV, (no IBU listed) Generally, the ABV% is about one-tenth the boil time in minutes, while the IBU is directly equivalent. Is this naturally due to the chemical reactions which occur during this part of the brewing process, or must Dogfish Head be doing something in particular which leads to an abnormally tight correlation here? <Q> First, it's important to note that the boil time is not the only thing that increases with each of those beers. <S> Dogfish Head continually hops during the boil, and the boil extracts the alpha acids from the hops, giving the beer bitterness, so a longer boil with more hops results in a wort that is more bitter. <S> In 120 Minute IPA's case, it spends an entire month in fermentation, resulting in an exceptionally high level of alcohol at the end. <A> There is no correlation between boil time and ABV. <S> The increased ABV stems from them adding more malt to balance out the extreme bitterness for the beers with longer boil times. <A> I disagree: boil time can affect ABV. <S> Assuming you're not trapping the steam, most of what boils off is water, meaning your final wort will have a higher O.G. <S> In general, that will result in a smaller quantity of a higher ABV beer. <S> (Of course, there are many variables, such as your yeast, your fermentation time, your ratio of fermentable:unfermentable sugars, and so on.) <S> Also, the starch->sugar conversion is generally terminated by your sparge (that being one of its purposes), so how fast you get to your boil doesn't have much of an impact. <A> As a note on the boil process and ABV. <S> Boiling effectively stops the process of converting starches into sugars which the yeast can turn into alcohol by destroying enzymes in the malt. <S> Therefore once you are boiling, this process has stopped. <S> Boiling affects hops, by boiling off the aroma and extracting more of the organic acids that provide bitterness. <S> This time and temperature affects how much of the starches convert and therefore trades between body and abv. <S> Boiling fast means you have a lot of body and low alcohol. <S> Boiling later means you have more abv and a lot less body.
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Here is where the additional alcohol comes in: To counteract the extra bitterness, the beers that have boiled longer have both additional malt added to balance the bitterness, and are given additional fermentation and conditioning time to allow the yeast to convert all of those malt sugars into alcohol. What does affect abv is the period of time the wort is kept warm before boiling.
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How can a beer be flavored? I've heard of beers such as our local brand in the Philippines and this one, and though I haven't sampled them yet, I am quite curious: how do you add flavor to beer? I've drank a few style of beers but I haven't dealt with any "flavored". As I'm not familiar with the brewing process yet, I want to know how as I don't think it's as simple as adding a syrup on the beer after brewing. <Q> Ok, so the basic brewing process is this (not homebrewing detail here, just a distant overview): <S> Heat your wort with water, steep, then add hops and boil, add more hops as you begin to cool, once cool enough add yeast, ferment, bottle. <S> Flavored beers can be made a bunch of different ways. <S> You can add herbs, spices, or flavorings before or after the boil, for example. <S> Seeds and roots would usually be added before the boil; herbs would usually be added after. <S> I would probably add fruit after but this is something that folks could argue about forever. <S> If you buy something like smoke-flavored beer, chili flavored beer, etc. <S> these are probably made this way. <S> There's a second type of flavored beer I have seen for sale in certain bars and restaurants in Asia though. <S> That's where you take a fairly light beer on tap and add it to a glass along with a shot of flavoring syrup (like lychee or peach). <S> These usually have sweeter flavor with clearer fruit flavors than the fermented fruit beers. <S> If the beer is pasteurized, the flavoring could be added before bottling and carbonation. <S> I think that is what you are seeing. <A> The Rogue Voodoo Doughnut Maple Bacon Ale is an interesting example because the ingredients list shows two different ways flavors can be imparted to beer. <S> The smoky bacon flavor comes both from the actual inclusion of bacon and from the smoked malt: Briess Cherrywood Smoked Malt, Weyermann Beechwood Smoked Malt, House-smoked Hickory Malt . <S> As discussed in Does chocolate stout contain real chocolate? , certain flavors can be achieved through the malting process rather than through additional ingredients. <S> Similarly maple is fermentable and could be added directly to boost alcohol content and impart a more subtle maple flavor. <S> That said, this beer does contain actual bacon and "maple flavor". <S> To get a look at and when and how the flavors are added, we can look at this clone recipe . <S> Name Amount Time UseFenugreek <S> 0.25 oz 5.0 min BoilMaple Extract 1.0 oz 6.0 days PrimaryBacon, cooked 4.0 oz 0.0 days Bottle <S> Here, fenugreek is added during the boil phase, while creating the wort. <S> The boiling helps extract the flavor from the herb. <S> Maple extract gets added later during fermentation. <S> Maple extract or syrup could be used, but syrup is more expensive and fermentable so a stronger maple flavor is being achieved with extract. <S> The official ingredient list calls for "Pure Maple Flavoring" <S> so I assume the same is being done there. <S> Lastly the bacon is being added at the end. <S> This is to add direct flavoring to the beer without interfering in the fermentation process. <A> I would like to add that although I have not confirmed it <S> I read somewhere <S> the purity laws had less to do with "making great beer" and more to do with them being poor. <S> They didn't want certain grains or things being used for beer as it drove up the price of bread and other foods. <S> In the following article it is states they didn't want to waste valuable grains for beer: April 23, 1516: <S> Bavaria Cracks Down on Beer Brewers . <A> Some types of hops have interesting flavors. <S> For example, simcoe hops has a pine-y, fruity taste. <S> Some interesting beer ideas would be pine, rosemary, or cardamom (I've had one - it was amazing). <S> Also, some white beers (like Hoegaarden) have coriander and citrus peel. <A> There is whole style of beer, which is made with honey. <S> It is made by adding honey to the wort during or before fermentation. <S> Thanks to addition of honey in early stages you get balanced, homogeneous taste. <S> Nothing to add that honey will ferment along with malt. <A> I just add it at the secondary fermentation stage when I homebrew beer. <S> I made a belgian style wheat beer and simply added some vanilla extract. <S> edit : I just added some cloves to a dark beer brew when decanting it out of my fermentation vessel. <S> Worked very well. <S> Additions don't need to be a liquid.
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Technically you can add anything to beer when it is ready (including honey), but then you get this aggressive flavor on top.
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Are there any medicinal uses for beer? Are there any common medicinal uses for beer? I'm thinking along the lines of how liquor can be used as an antiseptic and less of how red wine can improve your heart health. <Q> Just like wine, absolutely! <S> I'm not a doctor and I am not giving medical advice; I am not liable whatsoever for your drunken antics. <S> However, when abused, cardiovascular problems spike instead. <S> It helps to raise levels of "good cholesterol" which helps to keep arteries free of blockages. <S> It may help out your brain, keeping Alzheimer's disease at bay. <S> It is high in antioxidants and helps reduce your risk of cancer. <S> It is high in B vitamins, namely B6 and B12 <S> Moderate amounts of any alcohol, beer included, may help decrease your risk of stroke by reducing the chance of blood clotting in the cardiovascular system. <S> I highly doubt this one, but apparently, studies have shown a reduced risk of diabetes among men who drink occasionally. <S> Studies have shown that it has been linked to lower blood pressure. <S> It contain fiber! <S> Beta-glucans in particular, which are a soluble type of fiber. <S> Like sauerkraut, pickles, kimchi, yogurt, miso, and kombucha, beer is a fermented food, so many of the benefits of fermented foods such as aiding in digestion may apply to beer as well. <S> Yahoo Beauty 4 Health Benefits Of Beer Drinking: Antioxidants, B-Vitamin, And <S> Protein Are There... <S> But Don't Overdo It <A> Beer apparently not only lowers the risk of kidney stones, but also helps dissolve and pass existing kidney stones (additionally by dilating the ureters— <S> the tubes connecting the kidneys to the bladder). <S> Beer consumption was inversely associated with risk of kidney stones; each bottle of beer consumed per day was estimated to reduce risk by 40% [...] <S> Hirvonen, T. et al. <S> Nutrient Intake and Use of Beverages and the Risk of Kidney Stones among Male Smokers. <S> 1999. <S> [PDF] <A> There are a number of uses I have heard of people using beer for. <S> I will add a personal experience below as well. <S> I have heard of people washing their hair with it, believing it helps promote healthy hair and scalp. <S> Heavy, high starch beers, have long been used as a food source for fasting monks, sort of a liquid bread. <S> Beer is commonly used for cooking certain things because the alcohol (as with wine) helps bring out certain flavors. <S> Additionally I want to mention something I use it for. <S> This works for me because of very specific reasons and <S> I am not recommending that anyone else try it. <S> However, I get asthma frequently following upper respiratory illnesses (I have since I was a teenager). <S> I have a couple of alternative medical strategies for dealing with this depending on what is available. <S> Note, if you have asthma, don't take medical advice from me: asthma can be life threatening. <S> Work with a doctor. <S> This naturally works best when I am not otherwise consuming alcohol, but it allows me to be mostly medication free regarding my asthma (doing this two to three times a year). <S> Again this has a bunch of risks, so <S> I am mentioning it just for informational purposes. <S> Also some kinds of traditional beer have very specific health benefits. <S> In Indonesia, "tape hitam" (black rice beer, consumed with the lees as a sort of soup) is generally understood to reduce blood cholesterol. <S> As it turns out the helper cultures used are extremely close (and sometimes the same) as those which produce lovostatin. <S> In fact lovostatin was originally found in Chinese fermented rice products. <A> Not to be snarky, but there are as many uses for beer as there are people who use it. <S> I'm here because I use it, specifically high-hop/low alcohol (IPAs) as an alternate for sleep medication, since I don't want to be taking the same ones all the time. <S> (And though it's impossible to separate the sleep benefits, I think it helps with anxiety, not just at consumption time, too). <S> Beer, particularly the hoppy stuff, is known to raise blood estrogen levels. <S> http://goo.gl/qctfH3 . <S> Frankly, though I'm no expert by any stretch, I'd say a (that's one) bitter IPA at bedtime is the perfect prescription for menopausal insomniacs. <S> There's so much to read about beer and hormones. <S> To each his (her) <S> well-read own.
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With that said, in addition to kidney benefits: Beer contains high amounts of silicon, which makes bones stronger In moderation, it has been shown to lower the risk of cardiovascular problems. In general anything medical deserves a great deal of respect because what can cure can kill. However, among other things, I find that drinking a number of drinks of beer or wine for two nights in a row will cause the asthma to clear up until I get sick again.
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What are some ways to quickly cool a beer? It's happened to the best of us: you really want a nice hefeweizen or maybe a good bitter, but all you have are room-temperature bottles. Short of waiting an hour or so or (god forbid) putting ice in it, how can a bottle or can of beer be effectively cooled quickly? <Q> Take a bucket. <S> Or a bowl. <S> Or a cooler. <S> Or any other similar vessel. <S> Put your beer bottles or cans (sealed! <S> For the love of god, sealed!) <S> at the bottom of the bucket. <S> Fill it most of the way with ice. <S> Then fill in with water until the bottles are submerged. <S> Then throw in any remaining ice. <S> Finally, add a volume of salt commensurate with the quantity of water, both solid and liquid, you've already got in there. <S> Wait anywhere from 5 to 20 minutes depending on desired coldness and quantity of beer. <S> Enjoy! <S> (Rinse the rim of the bottle if you're finicky. <S> Also, this will probably ruin the label. <S> Sorry. <S> Why do you care about that anyway? <S> You weirdo.) <A> Another option might be some what less conservative, but instead of using ice cubes you could also use chilling rocks . <S> This is also often used as an alternative for cooling whisky without diluting it. <S> Soapstone is a non-porous, odorless and inert stone. <S> It is tasteless and will not absorb odors from your freezer like ice cubes do. <S> Soapstone has a high thermal mass, giving it the natural ability to retain its temperature for extended periods of time. <S> If you are a bit more patient, you can just put the beer in the freezer for about 10 minutes. <A> One method I know is to have large, heavy steins kept in the freezer. <S> That way as soon as you bring beer, you can cool it by pouring into the stein. <S> It won't cool your lukewarm beer to optimal temperature but it will give it a good few degrees drop. <S> You can use "reusable ice cubes", which are essentially tiny plastic bags with water - that way you won't dilute your beer. <S> There's also a stainless steel variety, it has slightly worse heat capacity but sinks to the bottom, which is less annoying than plastic bags floating in your stein. <S> I can't vouch if they don't affect the taste though. <S> A smart method though, is to use the buffer beer. <S> Remove the "buffer beer" from the fridge, put the the lukewarm beer in the fridge, drink the buffer beer - meanwhile the beer you put in the fridge becomes your new buffer beer ;) edit: if you go with reusable ice cubes, use ones that contain water inside. <S> Don't buy in to the scam of granite ice cubes or solid steel ice cubes. <S> Their thermal capacity is abysmal. <S> To provide the amount of temperature drop a single normal ice cube provides, you'd need to fill your glass with granite cubes to nearly the brim. <A> At the Defcon security conference in Las Vegas, the Beverage Cooling Contraption Contest is an exciting outdoor event. <S> Over the years, techniques have included adiabatic cooling (using a jet engine), dry ice, liquid nitrogen etc. <S> In 2008, this team managed to cool a keg of beer from 80F to 33F in 35 seconds using air power, dry ice and alcohol. <A> It takes a lot of time to cool a beer bottle in fridge. <S> But it takes much less time if you put them in freezer. <S> However, you shouldn't forget about such bottle, if you don't want the beer to freeze and explode the bottle. <S> If it's not fast enough, take a few glasses, pour a bit beer into each and put them all into fridge. <S> They will cool down much faster than the whole bottle, but the risk of making mess with broken glass is bigger, so it's better to check them each few minutes. <A> One method I've used seen to good effect is to wrap the bottle in wet paper towels, and then put that in the freezer. <S> Once the paper is frozen, the beer is quite cool, also the paper can be removed just by twisting it <S> and it comes right off. <S> Obviously, don't forget that you put them in the freezer to start with...
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I read somewhere about making ice cubes from beer somewhere, so that they don't dilute your beer (you need a good freezer for that though).
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Which are the most caloric beers? Are there, say, visual criteria to identify them? Is there a visual criterion to roughly estimate the order of calories a beer contains? Specifically, I wonder if "the darker the beer, the more energetic value it has" holds [1]. Please, prove or disprove. [1] (What lead to this belief: When I drink a trappist or a Guinness Extra Stout , both dark, I somehow identify the density with calories. But is that true?) <Q> No. <S> You can have a Belgian Tripel that is medium light bodied <S> , that has many more calories than a pint of Guinness, simply because the alcohol level in the Tripel contributes more calories than the sugars from Guinness. <S> Also Guinness is served on Nitrogen which creates the sensation of a thicker beer, as if there were more carbs and protein giving a fuller body. <A> Color does not effect calories it has. <S> There is a guide at Beer Data for calculating home-brewed beer, but I'd guess it might help you too. <S> cal per 12 oz beer = <S> [(6.9 × ABW) + 4.0 × (RE - 0.1)] <S> × FG × 3.55 <S> The first item in brackets gives the caloric contribution of ethanol, which is determined from the ABW and the known value of 6.9 cal/g of ethanol. <S> The second item in brackets gives the caloric contribution of carbohydrates, which is determined from the RE (Real Extract) and the known value of 4.0 cal/g for carbohydrates. <S> An empirically-derived constant (0.1) accounts for the ash portion of the extract. <S> Together, these terms give the calories per 100 g beer. <S> This is easily converted to calories per 100 ml beer by accounting for the final gravity (FG, in (g beer)/(ml beer)). <S> In turn, 100 ml is converted to 12 oz by a scalar (3.55, in (100ml/12 oz)) <S> Also, there is a list of Complete Beer Calories which lists the calorie content of 250+ beers with calorie and ABV values. <A> Considering that ethanol is the highest contributor to calorie count of a beer, and that the amount of remaining ingredients only vary to a degree, while variance in ethanol is very high, the odd modern beers with extreme extreme alcohol content will be the most calorical. <S> It appears currently Brewmeister Snake Venom is the top alcohol content beer, at 67,5%, with 2025kcal in 12 fl.oz serving. <S> The alcohol content runners-up don't top that by means of excessive sugar levels, therefore we can safely assume this is the most calorical beer. <S> Of course the competition in topping that is sharp, and we're soon to expect other beers with even more alcohol - and more calories as result. <S> There is no plain visual criterion to what beer has most calories, but you can safely correlate stated alcohol content with that. <S> ...also note: Alcohol is empty calories - calories that are not absorbable - storable by human organism. <S> A good mild caramel beer of 1.5% alc. <S> content might be more fattening than the top alcohol content beers, simply because it contains more sugar. <A> People usually forget to take into account the calories in beer and then criticism about increasing weight. <S> However, with Alcohol By Volume, you will have the understanding of beer alcohol content and carbohydrates in beer so that you can know just what you drinking so you could limit it in a manner which doesn't have any harmful effect on your health and fitness.
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The calorific load from a beer comes from both carbohydrates and alcohol, which are present in both dark and light beers regardless of beer color. Color has little to do with calories, and possibly surprisingly, mouthfeel can have little influence also.
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What's a good way to train your palate? Everyone knows how to drink beer, but it seems like it's an acquired skill to be able to differentiate (and articulate) different flavors. Whereas someone just turning 21 might say "this beer tastes... dark", a more experienced drinker might describe it as "nutty and chocolatey, with mocha overtones and black currents in the aftertaste." What are some good strategies for moving from the first quote to the second? That is to say, how does one train their palate for beer tasting? <Q> Flights! <S> I didn't know much about beers until I moved to San Diego, where I was introduced to beer flights <S> : <S> Somehow, I'd never heard of or seen them! <S> A flight is 4 or 5 small servings of beer, typically in 4.5- to 5-oz. <S> glasses, usually served on a "paddle. <S> " At least in San Diego, a flight costs as much as a pint on draught, so often it's a no-brainer to get flights if you want to taste a variety of beers. <S> When you order a flight, you of course get to choose what 4 or 5 beers you'd like to have. <S> I often select similar beers—a set of stouts and porters—or a bunch of IPAs (and doubles)—so <S> I can really get a chance to taste what distinguishes specific brands and subtypes. <S> When a friend of mine flew in from New York (also never having heard of flights), he was enthusiastic about getting two flights and sharing all 10—doing blind tests on one another. <S> He went from saying, before we got to the bar, "All beer tastes the same to me—I can only taste dark or light," to, " <S> Oh man, I didn't know I was even capable of tasting such little differences!" <S> So, beer flights are an effective yet casual and fun way to get yourself or anyone to appreciate the multifarious tastes of beers. <S> I think trying to start with all the ingredients, brewing processes, and the (dizzying) gamut of terminologies for all the subtle tastes, might be like teaching someone to drive by starting with the difference between torque and horsepower <S> —they can't fully appreciate the meaning of words until they've experienced the sensations they describe. <S> By contrasting beers side-by-side, we build an internal , as-of-yet-wordless "vocabulary" of tastes, e.g <S> "This beer has more of... that thing , whatever it's called, than this one," and then we learn terminology (and ingredients and processes) as a means of filling those voids in words for senses we've experienced. <S> Otherwise, we're storing abstract definitions, which we don't retain very well. <A> In a word, practice. <S> Most people drinking beer don't actually "taste" the beer properly. <S> They just drink it. <S> Of course, you do get some impression of the beer just from casual drinking, but it's not on the same level as if you are properly tasting it. <S> So, the first step to getting from the first quote to the second is learning how to taste the beer correctly and completely so that you can pick up all the nuances in the flavor and aroma. <S> How to sample a beer properly? <S> I think that's a good candidate for a new question! <A> Take Tasting Notes <S> It's easy to "just drink it". <S> If you want to really pay attention to the beer, there's nothing better than forcing yourself to write it down. <S> For example, I usually break it down into 4 sections: <S> Appearance: How much head? <S> How long did the head last? <S> What color was it? <S> What color is the beer itself? <S> Aroma: What do you smell? <S> How strong is the smell? <S> Taste: What do you taste? <S> How does that compare what you smelled? <S> How's the aftertaste? <S> Mouthfeel: <S> Usually just watery, oily, or creamy. <S> Tasting notes like this force you to really concentrate on the taste, which helps improve your palate. <S> They're also nice because you now have a record of your thoughts on that beer to refer to later (maybe to compare to other beers of that style).
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The format doesn't matter much, but I prefer a multi-part tasting form to force me to think about each part of the beer.
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What units are used to measure beer by volume? It may be dependent upon local custom, but what scales are used to measure beer? Is there one in particular that is used globally, or could be said to be specific to beer or alcoholic drinks? Typically, I see either pints or whatever the local standard of measurement for liquid is (say, fluid ounces or milliliters) so this isn't really a global standard. Serving sizes also aren't standard; in my country alone, if you go to a pub and ask for a pint or a schooner, the size will depend on what state you're in. However, I have seen the measurement l (lower-case L) used. Is this litres, or something else? <Q> Beer is measured by volume, but which measure depends both on country and on the context in which the measure is being used. <S> However, in production, you will regularly find the measure being listed in barrels (31 imperial gallons). <S> You'll regularly find beer sold in pints (16oz), though that could also mean a 20oz glass as you only get 16oz of beer with a proper head. <S> My limited experience with bits of Europe indicates beer there is sold by the mL. <S> Also worth noting is that Liter can be represented as <S> either L or l <S> so when you see "l" you're seeing Liters. <S> So, no. <S> There isn't a global unit of volume for beer. <S> But it is almost always sold by volume . <S> Also, with the rising popularity of high gravity beers, standard beer servings vary in part because to serve similar amounts of alcohol across standard servings you've got to serve differing quantities. <A> In the UK, beer in Bars and Pubs is still sold in Pints, even though EU regulations require the actual quantity to be described in metric units. <S> But asking for a "pint" is a lot easier than asking for "586ml of beer please barman". <S> (Note that they use imperial units in the UK, and UK pint is bigger than it's US counterpart.) <S> Bottled beer is invariably sold in 500ml bottles or 330ml bottles. <S> In Scandinavia, and I believe most of Europe, beer is sold in half liters (500ml) in bars, while bottles are typically 500ml or 330ml. <A> In Germany, beer in bars and pubs is sold in jars of varying size. <S> Different ingredients, different yeasts (top fermented or bottom fermented), different jars, different traditions. <S> In the Cologne area, the traditional beer Kölsch is sold in traditional jars of 0.2 l (200 ml). <S> It should be drunken quickly and therefore smaller glasses are appropriate. <S> Some pubs use 250 ml as their standard size however. <S> Usually larger glasses are also available (300, 400, or 500 ml). <S> In Bavaria, standard sizes are rather 500 or 1000 ml. <S> Standard bottle is 500 ml, but many brands also offer 330 ml bottles.
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For instance, in the US, you will almost always find servings of beer measured in fluid ounces.
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What are the defining characteristics of a Saison? What should I expect when I drink one? I'll be the first to admit that I have, at best, the palate of a highly experienced amateur. I can tell an IPA from a Stout from a Doppelbock primarily on the common visual, olfactory, and above all else tastes that are found throughout any example of each style. However, while I've had many delightful 'Saisons' in my time as a drinker of beer, I've never been able to get a straight answer about what characteristics define the style. The best I've ever been able to get is vague handwavey historical notions about the beers role as a 'refreshing summer ale'. Which is... somewhat unsatisfying to someone who would hope that the term might actually mean something . So, does it? If so, what? If I pick up a Saison from a brewery I've never heard of, what characteristics should I expect it to exhibit that earn it the name? <Q> Well, Saison is quite a broad category simply because it comes from a broad definition. <S> The original term comes from regular strength light ales ca. <S> 3.5% abv) brewed during the Autumn in Belgium, and stored for drinking in the summer by farm workers. <S> (Hence the pseudonym "farmhouse ale".) <S> As wikipedia states: <S> Historically, saisons did not share identifiable characteristics to pin them down as a style, but rather were a group of refreshing summer ales made by farmers. <S> In modern times, the category has been interpreted to mean: a light to golden ale use the Dupont yeast, which gives particular esters and pepper characteristics <S> (hence they have a "Belgian" character) <S> around 7% abv fruity, spicy (some examples add fruit, such as apple juice.) <S> highly carbonated <S> This might seem quite vague, but the combination of yeast, light malt, strength and carbonation lead to a fairly unique and identifiable beer. <A> I agree with mdma that it's traditionally more of a historical definition than a stylistic one. <S> To expand on their answer, though, in 2008, the BJCP defined a saison as the following (abridged): <S> Aroma : <S> Some coriander, with a complex herbal, spicy, or peppery note in the background. <S> Moderate zesty, citrusy orangey fruitiness. <S> Appearance : <S> Very pale straw to very light gold in color. <S> Cloudy. <S> Flavor : <S> Pleasant sweetness and a zesty, orange-citrusy fruitiness. <S> Crisp with a dry, tart, finish. <S> Can have a low wheat flavor. <S> Optionally has a very light lactic-tasting sourness. <S> Herbal-spicy flavors, which may include coriander and other spices; subtle + not overpowering. <S> Mouthfeel : Medium-light to medium body; <S> effervescent character from high carbonation. <S> Minimal bitterness in finish. <S> For more detail, see the full version . <A>
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Moderate sweetness with light, grainy, spicy wheat aromatics, often with a bit of tartness. There was another source that I read (probably that 1000 page beer encyclopedia that I forgot the title of) where they said that a saison was made with whatever ingredients that were available at hand at that season.
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Drinking from a pewter mug? Modern beer is typically served in glassware, and the reasons for the various styles are addressed in What glasses are meant for which beers and why? I have some alternative vessels at home, including a pewter tankard. The problem I have with drinking from it is that the pewter has a slight tang which you notice on your lips and the tip of your tongue. Depending on the the style of beer, this can either enhance or detract from the taste. (Personally, I've noticed that hefeweizen benefits from the slight acidic tinge, while some Lagers are really undrinkable from it.) Are there any styles of beer for which it's actually advantageous to drink from something other than glassware, like pewter? Say, for example, they've been brewed specifically to pair well with the material of the vessel. Alternatively, should I even be drinking from this kind of vessel at all? While it's documented that pewter and other materials were used historically to make tankards, should I even be bothering today or is it just a gimmick? <Q> To be honest, I think drinking carbonated (with CO2 at least) beer from pewter is asking for trouble if you do it regularly. <S> The tang you feel is dissolved metal and a component of that, depending on the pewter, may be lead (or could be copper, tin, bismuth, antimony, etc). <S> A major factor in that is acidity, and both hops and carbonation contribute. <S> Acidic solutions react with metals to produce hydrogen gas and dissolved metal salts. <S> So carbonic acid from carbonated beer will react with the tin to produce hydrogen and tin carbonate, and the same basic process with other metals. <S> The specific metal that reacts will depend on the pewter. <S> There are some ways around this. <S> You could, for example, coat the inside of the vessel with bees wax. <S> This can then be washed by hand with hot tap water and soap (and is a common method in making drinking horns). <S> This has the pro/con (depending on your taste) of imparting a slight honey taste to everything you drink out of the vessel. <A> There really isn't any reason why a modern pewter tankard would be harmful to drink from. <S> Lead has been illegal in pewter drinkware in the USA and western europe (at least) for decades now. <S> The FDA is widely considered VERY risk-averse and they are fine with pewter when it doesn't contain lead greater than a trace amount (see FDA regulation 4-101.13(B) ). <S> The other metals in pewter - mostly tin, with some copper and (usually) antimony - are very unlikely to cause a problem because they won't be absorbed into the beer in any material quantity, and because they are generally not harmful if they were absorbed (see this page about pewter tankards ). <S> Remember tin's role as a coating for the inside of food containers? <S> NOTE : <S> older pewter may well contain lead, and this is soluble in beer, and this is not safe. <S> The lead dissolving is what causes 'pitting' on the inside of older pewter tankards. <S> I enjoy both. <A> You're right to have identified a peculiar flavor coming from pewter. <S> There are two parts to this: the leaching of the metals as mentioned by @Chris as well as the oxidation of lipids in your mouth. <S> In my opinion neither of these is particularly pleasant. <S> That being said, when pewter was phased out in favor of glass, there were many who held on to their pewter tankards for drinking porter. <S> Ron Pattinson shares an anecdote about an Irish MP who would hide his pewter mug under the table to avoid the critical eye of others in the pub. <S> Today you might get a similar reaction from craft beer drinkers appalled at your treatment of the beer.
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As to whether it's more enjoyable to drink out of glass or pewter, really comes down to personal taste.
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Are there any good uses for beer that has sat in my growler for too long? I usually try to drink all of the beer in my growler over the course of two nights. While the second serving is usually a good bit less stellar than the first it's usually still quite drinkable. However, because I almost always plan to drink it over two nights, sometimes the second half of the growler gets left a few days longer. After that it's basically undrinkable. Usually I snag Imperial Stouts, or other high gravity brews (currently I have a Southern Tier Creme Brulee ripening in the fridge :(). Is there a good use for this spoiled beer or should I just pour it out? I was wondering if beer bread was a good idea or not. <Q> However, if it is only a few days old and has been in the fridge, it's unlikely that it's done much more than go completely flat, so any use that doesn't require it to be carbonated would be fitting. <S> -- I'd go for the bread. <A> In my experience, many recipes that call for beer either work fine with flat beer or call for it that way. <S> Examples include chili, fish poached in beer, and some stews. <S> Some recipes seem to rely on the yeast in the beer and others add bread yeast, so check in order to avoid baking a hockey puck. <S> This is for conventional bread. <S> If you're making a quick bread that uses baking soda, you don't need help from the beer for rising. <S> (Thanks waxeagle.) <A> Cooking with beer is always a good decision, and stouts are a prime choice. <S> Since it doesn't matter if they're a little flat, why not try some? <S> Beef and Guinness Stew Cheese and beer soup Chocolate stout brownies <S> Beer battered anything <A> I'd definitely say cook with it as others have mentioned. <S> You're really just trying to impart <S> some of the beer flavors into the food; you don't really need a fresh beer to do that as carbonation doesn't affect the flavor, it affects the mouth-feel. <S> If it's only been 2 days, it probably hasn't spoiled, so you're fine. <S> Beer bred is always an option. <S> I also saw someone else on here mention <S> Polish Beer Soup .Beer <S> -battered fish is another option. <S> I could go on and on with recipes though. <S> The Brooklyn Brew Shop has a lot of interesting ones that I've never seen before, such as french toast (might be good with a chocolate stout or other dessert stout) and beer braised greens. <S> Household uses include trapping insects in your home, washing hair, fertilizing plants, cleaning wood furniture, etc . <A> Making it into a marinade for steaks would work. <S> Though I find that the darker beers are the best for this. <A> You could use it to make steak and ale pie, this works particularly well with darker beers. <S> Although you don't need much - about 1 cup / 220ml. <A> Another option is to make your own malt vinegar . <S> You can just put a piece of cheesecloth over the top (with the cap removed), or you could add a little vinegar mother, like from the bottom of a "natural" bottle of vinegar, and it will turn it to vinegar for you. <A> I've seen a lot of people commenting to cook with it , which is my advice , but I haven't seen someone speaking about crepes. <S> I don't know if we only do this here (france) <S> but I've always used beer to make crepes and <S> it's realy great. <S> I recently thought about using strong flavored beers (like dark ones) but didn't try it yet <S> so if you try it soon a feedback would be appreciated !
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Depending on the type of beer, I would also consider using it for boiling sausages/bratwurst with it. Supposedly washing your hair with it has some nice effects,and people have found other creative uses: How to make good use of flat, leftover beer from your Christmas party . I would be reluctant to use it for bread unless the recipe calls for a "normal" amount of yeast, though. The carbonation from a fresh beer would be lost in cooking anyway.
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Why do steins have lids? What's the point of the lid on the beer stein? <Q> Today they're largely just traditional. <S> However, originally they helped: <S> To keep the beer cool by preventing airflow from above. <S> To keep insects and other contaminants out. <S> To prevent spillage while cheers-ing and generally carousing. <S> See the following article on Stein Lids for more detail. <A> From about 1340 until 1380, a bubonic plague, or Black Death, killed more than 25 million Europeans! <S> As horrible as this historic event was, it prompted tremendous progress for civilization. <S> And, of interest here, it is also responsible for the origin of the beer stein. <S> Recall from above that the distinction between a mug and a stein is the hinged lid. <S> This lid was originally conceived entirely as a sanitary measure . <S> During the summers of the late 1400s, hoards of little flies frequently invaded Central Europe. <S> By the early 1500s, several principalities in what is now Germany had passed laws requiring that all food and beverage containers be covered to protect consumers against these dirty insects. <S> The common mug also had to be covered, and this was accomplished by adding a hinged lid with a thumblift. <S> This ingenious invention was soon used to cover all German beverage containers while still allowing them to be used with one hand. <S> - A Brief History of Beer Steins. <S> For more information one should read <S> The Beer Stein Book: A 400 Year History. <A> Beer with hops will get skunky shortly after exposure to sun light. <S> Exposure of about 15 seconds and you can smell the change start if you hold it to your nose in bright sun light. <S> I have one and use it during outdoor barbecues. <A> My Austrian father-in-law tells me that they're also handy for keeping ashes out of your beer. <S> I don't smoke, so that had never really occurred to me until he mentioned it. <A> I believe the lid was also used during the Revolutionary War to keep the Kings naval soldiers from throwing a British coin into the beer of an unsuspecting drunk colonist in a tavern. <S> Legend has it that once the ale was consumed, the remaining coin would signify that the owner of the stein would be incriminated by default, to the loyalty of the King. <S> He would then be immediately drafted into the Naval Army of the King. <S> Consequently, the need for a glass bottom to the stein was adopted as a precaution for colonists to be able to see the naval officers by simply lifting up the stein and prevent capture..
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The steins with their lids seem to have come about as a result of the bubonic plague to serve as sanitary measure and thus keep flies and other insects (fleas) out of the beer.
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Can quick beer cooling have a negative effect on the beer's taste? Is there a difference if we compare the classical cooling of the whole keg : and the quick flow cooling where the keg is at the ambient temperature? Can the quick cooling have negative effect on the beer's taste or head? <Q> As long the beer's sealed, there should be no difference in taste due to rapid or slow cooling. <S> Lowering the temperature only increases the solubility of CO 2 , which should dissolve later. <S> Temperature itself does impact taste, supposedly due to our taste buds being number in cold, hiding certain flavors (which can be desirable or undesirable depending on the beer). <S> But this isn't related to the rate of cooling of beer. <A> I can think of three possible impacts this scheme might have on a keg of beer. <S> Since the keg is kept at room temperature, if the beer is unpasteurized the flavor will evolve at a faster rate than refrigerated beer would. <S> This isn't a change due to the quick cooling, per se, but it is a possibly major difference. <S> As mentioned by @acheong, the CO2 solubility of beer is significantly lower at room temperature, so keeping the beer properly carbonated becomes a more difficult task. <S> Specifically, you have to keep the pressure much higher, making the serving pressure higher, which makes the complex calculus of draft line measurements that much harder. <S> Chill haze could be an issue. <S> If the brewer didn't take steps to prevent it, there'll be haze-inducing proteins in suspension. <S> If the beer is stored cool, these will quickly fall out, but if it's kept warm and only cooled at the time it's served, they'll end up in your glass. <A> In short, no. <S> However there are certain temperatures that are preferred for serving certain beers. <S> The most damaging thing to beer flavor is light pollution. <S> When in direct light, isohumulones from the bittering agents in hops can react with riboflavin (Vitamin B2) in beer and produce 3-methylbut-2-ene-1-thiol (MBT) which has a noticeable skunky flavor and aroma.
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The time it takes to cool a beer will not have an impact on the flavor of a beer.
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Which types of beer are commonly used for half-and-half beers? Which types of beer are commonly used to create half-and-half beers? In frequent recipes are only beers of contrasting colours being used (like pilsener vs porter or pale lager vs stout) or other combinations are being commonly used too? What are some of the most popular recipes? <Q> In a Half and Half (also known as a "Black and Tan" in certain locations), the primary factor will be the density of the two beers -- one beer must be of a lesser density than the other to stay afloat. <S> Contrasting colors are used for visual effect; otherwise, how might you know one was floating? <S> Its Guinness' particular light density that makes it a good candidate for so many half-and-half style recipes. <A> I think it all depends on your personal preference. <S> Shock Top, for example, released a six pack that featured their Chocolate Wheat and their Belgium White. <S> What I would do is think of a dark beer you enjoy <S> and then a lighter (but still flavorful beer) <S> that you like and just experiment with mixing them. <S> In my case I would choose to mix Left Hand Milk Stout and a Kentucky Kolsch. <S> Let me know what you try! <S> I am curious! <A> A half and half is a Guinness with Harp. <S> This style of beer combination is accomplished by using a dense beer on the bottom followed by a beer of lesser density on the top (usually poured over a spoon to ensure that it doesn't sink through). <S> Essentially it is usually an ale or lager underneath a stout. <S> Some popular versions and combinations include The Trinity Guinness, Smithwicks, Harp Blacksmith Guinness & Smithwick’s Irish Ale Black & Black Guinness & Guinness Stout Black Pyramid Guinness & Pyramid Black & Gold Guinness & Magner’s Cider Black & Red Guinness & Killian’s Irish Red Black & Sam Guinness & Sam Adams <S> Black & Fire Guinness & Firestone Black Coffee Guinness & Black Butte Porter <S> Eclipse Guinness & Blue Moon Black Castle Guinness & Newcastle Black on Blonde Guinness & Stella Artois Black Tire Guinness & Fat Tire <S> Dark & Steamy Guinness & Anchor <S> Steam <S> Irish American Guinness & Budweiser The Noogie Guinness & Pabst Blue Ribbon Half & Half Guinness & Harp Black & Tan Guinness & Bass <S> San Patricios Guinness & Corona <A> At our local pub the Eclipse <S> (Guinness & Blue Moon) is also referred to asa Dark Side of the Moon Black Raspberry - Guinness w/ Lindemans Raspberry Frambois Black Death - Guinness w/ Black Widow Cider <A> Personally when creating a "Half and Half", Guiness is the only constant. <S> The other beer is usually something only lighter in color. <S> Wheat beers have an interesting flavor. <S> IPA's have their bitterness cut when made into a Half and Half. <S> Beyond that, I will sometimes select the beer so that the drink gets an awesome name: <S> Black and Blue - Guiness <S> w/ Labatt <S> Blue Black Sunset - Guiness w/ Leinie's Sunset Wheat Black Cow - Guiness w/ New Glarus Spotted Cow <A> Guinness isn't the only dark beer to layer with. <S> Check it all out at The Perfect Black and Tan. <A> It is more than color. <S> You need the other beer to have a different density from Guinness, at least if you want it to stay separated for any length of time. <S> And be careful which Guinness you use because there are a number of them out there with different "strengths". <S> If the densities are too close, they'll mix together. <S> A good starting point in selecting interesting combinations is to look at the densities across different styles . <S> Pick two that are widely different and find bottles of each. <S> For instance, if you take a bottle of a kriek (red-looking fruit lambic), it would probably float nicely on most other beers, but you'd want to pick a nice, dark beer to show off the contrast (plus, if you used a kriek (cherry) or frambois (raspberry), pairing it with a porter or stout that has nice chocolate tones would taste very nice). <S> Likewise, just about anything would float on a bock or a strong scotch ale like a "wee heavy". <A> I just asked for a half and half but this place didn't have Guiness so the bartender told me to try it with Murphy's and Harp instead. <S> Total fail. <S> The densities were too similar and one mixed into the other. <S> Not awful flavor just not a Black and Tan. <A> Guinness and Harp - a Half & Half Guinness and Ale - Bass, Smithwick's, or John Courage is a Black and Tan. <S> The thought of attempting to properly pour either using lite beer is deplorable!
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Common recipes involve floating the less dense Guinness over a Bass, or a Guinness over a Harp Lager. Black Torpedo Guinness & Sierra Nevada Porters can be used to as a bottom layer to give you a dark-on-bottom drink. There are many different combinations out there such as the Black and Tan, but some companies have also started coming out with six packs that they intend for you to mix.
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What's the difference between a cask beer and a kegged beer? Cask ales seem popular outside of the US (especially in the UK). What distinguishes that style of beer from beer out of a normal keg? <Q> Cask ales are not stored under pressure , and require a pump to transfer the beer from the cask. <S> As the ale is not under pressure, it is also not as heavily carbonated as other beers. <A> Cask beer is not kept under pressure whereas Keg beer is (with CO2 or a nitrogen mixture). <S> Beers served in Cask vs Keg (w/ CO2) <S> vs Keg (w/ Nitro) will have slightly different tastes and appearances. <S> Cask beer will be a "flatter" due to the lack of pressure keeping the CO2 in solution in the beer. <S> Cask beer can also take on a butterscotch flavor due to the exposure to air. <S> Hoppy beers will be mellowed in the Cask vs in a Keg. <S> Beer in a cask needs to be drank within a few days of opening the cask due to the exposure to oxygen. <S> Kegs served with CO2 <S> are typically how beers are served. <S> If the keg is using a Nitro tap, the beer will get a smoother milky texture due to the gas and the head will cascade in waves. <S> The beer will last much longer in a keg because of the gas keeping oxygen away from the beer. <A> Depends on who you ask. <S> Both of these answers are correct but some would take the definition of cask ale a little further by defining it as an ale that is unfiltered and unpasteurised and conditioned (including secondary fermentation) and served from a cask without additional nitrogen or carbon dioxide pressure. <S> One of our local beer shops has a few cask ales on tap, ran by someone from England. <S> He often scolds beer sold as cask ales which were only placed into the cask after fermentation is completed.
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In contrast kegged beer is stored under pressure, and is forced to the tap by pumping gas into the keg (usually carbon dioxide or nitrogen).
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How was beer brewed before the discovery of Yeast? Yeast was identified as the cause of fermentation in the 1800s, but beer has been around since long before then. How was fermentation started before the intentional introduction of yeast? Was it all lambic-style ambient yeast, or what? <Q> You don't need to know what something is to use it effectively. <S> Though yeast was only identified as a microorganism recently, it has been known as the cause of fermentation for many centuries. <S> It's easy to underestimate how sophisticated people throughout history were. <S> Before yeast was monocultured in labs it was actively cultured by brewers. <S> They would transfer the yeast cake from a batch that's finishing into a recently-brewed batch. <S> This cake contained a whole ecosystem of yeasts and bacterias, but a few strains were usually dominant. <S> By applying artificial selection brewers developed different strains of yeast in different areas. <S> The yeast culture was the make-or-break characteristic of a brewery, and defined the styles of beer that could be produced more than any other factor (other than water in Burton). <S> Evidence of this process comes from the history of lager: bottom-fermenting yeast (Saccharomyces carlsbergensis) emerged in the fifteenth century as a direct result of the cold storage regime of northern brewers such as Carlsberg. <S> They may not have known it was a microorganism, but middle ages brewers most certainly knew that yeast was the cause of fermentation. <S> That's why they called it "Godisgood". <A> There are many plants where yeast grows in symbiotic mutuality. <S> Take fresh dark grapes - the slight white "sediment" on the surface is natural yeast, and you won't find grapes without it. <S> Another such plant is barley. <S> Normally, the yeast only appears on the seeds, in relatively small amounts. <S> Malting creates optimal environment for the yeast growth though, making the whole volume of the seed (as opposed to just the surface) nutritious for the yeast, and as it grows, it produces alcohol. <S> Sure there is always a risk that a different culture of fungi or bacteria takes over, killing off the yeast (and e.g. producing vinegar instead of alcohol) but if brewing is performed in relative cleanliness, with little contaminants that could disrupt the process, the natural yeast will take over and dominate it, killing off all competing cultures. <S> Currently, cultured yeast provide a kick-start to the process, simply leaving no time for different cultures to dominate the batch, and radically shortening the process that would normally take a long time until natural yeast reaches concentrations you create by just adding cultured yeast, but it's not essential to the process <S> - it's just a strong push in the right direction. <A> Actually, there are still people who brew the same way people did before the discovery of yeast, so we have a pretty good idea how it worked. <S> There are also data from early 20-th century ethnological surveys where brewers describe their methods. <S> Some of the equipment used for yeast transfer is still in use, or in ethnological museums. <S> People usually didn't brew that often, so they couldn't transfer the yeast cake itself. <S> Instead, they would collect yeast from the previous brew and either keep it in a jar that they kept cool, for example in a well, or by drying it on a wooden log, piece of linen, straw ring, etc etc etc. <S> There were lots of methods, but they basically boil down to either keeping wet or dry yeast. <S> Odd Nordland's 1969 book is the only detailed source of information on this that I know; unfortunately it's near-impossible to get hold of. <S> As far as I know, this type of yeast and yeast use only survives in two places: <S> the Lithuanian province of Aukstatija, and western Norway (specfically, Hardanger, Voss, and Sunnmøre). <S> I've written a summary of what's known of Norwegian practices , and earlier this year I was able to brew with a brewer who still uses his family's ancestral yeast strain. <S> I've published an account of that brewing session . <S> I hope people will forgive me for linking to my own stuff here. <S> I don't know of any other detailed sources of information on the web anywhere. <A> There is no production of alcohol without yeast. <S> Bevore the "discovery" (better: selection and cultivation) of the Yeasts we know and use today, humans had to rely on luck. <S> Its a wild fermentation, many different microbes and fungi are competing for their nutrition (sugar). <S> The problem here is: Many yeasts produces fusel alcohol, i.e. methyl alcohol (which can cause blindness).Other bacteria could cause the fermentation to vinegar. <S> So the resulting product seldom was good, mostly it was not drinkable for us today <S> ;) <S> Since the cultivation of special yeasts it's possible to control the fermentation, while adding a big amount of the yeast. <S> So this yeast has a big advantage over others. <S> Further the produced alcohol and carbondioxyde protects the beverage from other organisms. <A> Louis Pasteur discovered the importance of yeast to brewing in 1857. <S> Ancient brewers still used the same process of mashing the grains to extract sugars for fermentation and adding hops for bittering and preservation. <S> As a side note, prior to the use of hops in brewing brewers used a mix of herbs called "gruit" which provided flavoring but no preservation. <S> Certain areas of the world are known to have wild yeasts better suited to brewing and still produce beers of this style today, such as Belgian lambics. <A> Yeast as a microorganism was discovered by Pasteur. <S> The Vikings did not have microscopes, likewise neither did the Germains who wrote the beer purity law of 1516 which does not include yeast as in ingredient. <S> Brewers (often clergy or women called "brewives") believed it was a mystical process and kept beer consistent by saving sediment in patties or cakes for the next batch like bakers save chunks of dough. <S> The term yeast may have been used before pasteur but he surely changed the meanining and revolutionized standardized beers by isolating yeast types. <S> As far as I know beers that rely on wild yeasts are the "farmhouse" styles compared to the main two; lager and ale yeasts.
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Before brewers discovered the importance of yeast in the brewing process they had to rely on the local wild yeasts for fermentation.
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What type of beer require the most time to produce? Of all types of beer, what type of beer require the most time to produce? <Q> The most time? <S> I'd think Gueze. <S> It is a blend of 1 and 2 (and sometimes 3) year old lambic. <S> So the minimum time to produce would be 2 years. <A> In addition to what's said, a major caveat is sour beer. <S> Modern breweries have managed to coax and trick lagers into being ready without months of expensive aging, but there is no way to hurry a sour. <S> The bacteria and wild yeast strains that make those flavors require specific conditions, and changing those conditions changes the rates of their activity and the flavor of the beer. <S> Lambics in particular are often blended and contain "young" beer, which is only a year old, and "old" beer which can be 3 or 4 years, or more. <S> Then the beer is aged an additional year in the bottle, but can be kept for 10 years or more. <A> The time it takes to make beer can be anywhere from 10 days to several months. <S> There are a few factors that determine how long a beer takes to be ready to drink. <S> The original gravity of the beer (gravity measure the amount of sugar in the wort), the type and strain of yeast used, and alcohol content of the finished beer. <S> Other factors such as any adjuncts used in the beer can affect this as well. <S> For example, a low gravity, low alcohol ale using an efficient yeast strain can be ready to drink in as little as 10 days. <S> However a heavy lager beer can take 2-3 months to complete and some Belgian yeast strains can take several weeks to complete fermentation. <S> This conditioning may include simple bottle conditioning or barrel-aging to impart different flavors. <S> There are some barrel-ages stout beers that have taken 18+ months to complete the process before the brewer feels they are ready to serve.
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Some beers go through additional conditioning post-fermentation before they are at their prime to drink.
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Should English/English-style beers be served warmer, since that is how the taste was developed? Given that the British tend to drink their beer at a higher temperature than those of us in the US, should beer brewed in an English style be consumed that way? The justification I can think of is: the people developing the taste of the beer probably consumed it at a certain temperature, which might have not been the ice-cold levels that predominate in the Colonies. <Q> Serving temperature is, of course, a preference. <S> Serve it frozen or boiling if you want. <S> However, a few opinions are: CAMRA says that Real Ale (aka cask ale, usually english-style) should be served at 12-14 °C (54-57 °F), which is colder than room temperature, but warmer than your usually keg beer. <S> Ratebeer says the same thing regardless of whether it’s cask or not. <S> BeerAdvocate says 7-10 <S> °C (45-50 °F) for an english bitter. <S> So, if you’re looking for a rule of thumb: “cool but not super-cold” or “cellar temp” will probably get you close enough. <A> There may be a general consensus for the "proper" serving temperature, which could involve questions like "what do most people seem to like?", and "what temperature does the brewer feel best accentuates the parts of the beer they want to highlight?". <S> So there are good reasons for beer to be served at particular temperatures. <S> As for a modern British beer, I suppose that would depend on what the brewer had in mind. <S> That said, my general thought is that you should drink a beer at the temperature you most like it, so the should part of your question is self-determined, and don't let anyone tell you that your taste buds are wrong. <S> Myself, I tend to like my American IPAs cooler than the typical recommended serving temperature. <S> And before I visited the UK, I couldn't stand a room temperature beer. <S> Then, after a week in Tunbridge Wells, I picked up a large appreciation for hand-pumped UK beer, served at room temp. <S> So you should open yourself to trying new things as well. <A> I alway say that the darker the beer, the warmer it has to be, so here are my rules: - Light beer/White beer/Kriek : In the fridge and goes in the freezer for a couple of minutes before serving - Golden beer : In the fridge - Amber beer : In the fridge and stay at room temperature for a couple of minutes before serving - Dark beer : At room temperature and goes in the fridge before serving - Stout : At room temperature at all time. <A> The basic rule is that beers should be served at the temp they were fermented. <S> Lagers should be served at about 40°F and ales around 50° <S> F - 55°F. <S> Having said this I usually like my beers a little colder on a warm summer day. <S> Try this experiment: chill your beer to 35°F - 40°F and pour about 2/3 of it into the proper glass for that beer. <S> Drink at least 4 or 5 sips, gulps, or however you typically consume it. <S> Then put what is left in the microwave for about 20 seconds <S> (time will vary with the output of the microwave). <S> This will reduce the carbonation some so pour the other third right in the middle of the glass without tipping the glass to get some head, on the beer that is. <S> It makes a big difference on some beers. <S> less on others. <S> Also try different types of glasses and see what you like. <S> Remember, everybody's palates are different and yours will vary depending on several factors such as, what you've been eating or drinking, how much beer you've already consumed, and how tired you are. <S> It's a good idea to eat a bite or two of good bread like a baguette to cleanse your palate between samples. <S> The above does not apply to mass produced lagers. <A> It's always going to be a matter of preference. <S> I prefer most beers around 55-60 but do not hesitate to drink beer at room temperature. <S> Some styles are more enjoyable approaching room temperature. <S> Historically, most beer was served at cellar temperature to room temperature, depending upon what was available. <S> That isn't just an English tradition. <S> Any beer can be consumed warm and drinking it ice cold as mass produced lagers are usually served tends to hide most of the flavor that you are paying for in a good beer. <S> Give it a try and see what you like. <S> Maybe you don't like your beer a little warmer. <S> Enjoy what you like. <A> First, let's say there is what is considered "proper", and then there is personal-preference. <S> To be a good Cicerone, know what is "proper" but also show tolerance for personal preference. <S> With that out the way, it's definitely considered the "proper" thing to do to serve English beers warmer than ice-cold. <S> Many of the delicate malty flavours you get from English malt <S> , the fruitiness from esters produced by the English yeast, plus grassy, herbal or floral tones from the hops are muted greatly when the beer is served too cold. <S> Some people say it's served at room room temperature. <S> Modern room temperature of around 20°C/68 <S> °F is too warm. <S> The ideal serving temperature is a cold cellar - typically around 12°C;55°F.
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In the case of your British bitters, age-old recipes were probably designed to allow the beer to taste its best at room temperature. Just like everyone else said, it's a preference.
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Will drinking too much of beer increase the size of belly? Someone told me that drinking beer will increase the size of our belly. Is it true? Since I don’t drink beer, I don’t have any idea about that. <Q> Just like any other calorie intake, if you consume more than you burn, you will gain weight. <S> So, yes, drinking "too much" beer will "increase the size of belly". <S> What "too much" means, however, is dependent on your other habits. <S> The typical "(beer | pot) <S> (belly | gut)" is usually " Abdominal Obesity " which, by definition, means obesity in the abdominal area specifically, i.e. the belly. <A> A beer belly comes not so much from beer and the frequent drinking of it as it does with the food that is typically associated with beer (for example, burgers, pizza, etc... very high in calories). <A> Well, yes, beer has some calories, according to this article; <S> The Truth About Beer and Your Belly : <S> A typical beer has 150 calories – and <S> if you down several in one sitting, you can end up with serious calorie overload. <S> but read further Alcohol can increase your appetite. <S> Further, when you're drinking beer at a bar or party, the food on hand is often fattening fare like pizza, wings, and other fried foods <S> I've heard from a lot of people that beer increases appetite more that other alcoholic drinks, and in fact beer pairs very well with such calorie rich food as pig knuckle, or similar... as well as pizza, chips etc. <S> If you compare calories in beer and pig knuckle you'll see what is more likely to cause obesity. <A> Calories are calories. <S> A typical middle-aged male needs about 2100 calories per day. <S> Consuming more calories than this per day will increase your weight. <S> If you drink four 12-ounce regular (5%) beers per day, you will add between 500-700 calories to your daily diet -- depending on the style of beer you consume, meaning its sugar content, which will vary with beer style. <S> This calorie range translates into around 3500-5000 extra calories per week, which is equivalent to gaining about 1.0-1.4 lbs of weight per week if this calorie intake is above your body's minimum requirement (ie: 2100 x 7 days). <S> After 3 months you will have gained anywhere from 13-18 lbs. <S> It doesn't matter what you eat or don't eat along with your beer. <S> If your beer drinking brings you over the 2100 calorie per-day threshold, those calories will show up as fat in your body. <S> All of this assumes no exercise. <S> If you are active and can burn off 300-500 calories a day through a combination of working out and regular body movement (general walking, going up and down stairs, prolonged upper-body activity), then you will cut into that calorie gain in proportion to your activity. <A> Drinking beer alone does not cause you to get a big belly, it's the amount food that goes along with it. <S> People usually drink beer in the evening, and tend to eat a lot of food at the same time. <S> And this is great and dandy, but what people forget about is that they eat late (here combined with drinking beer so even more calories), and then go straight to bed. <S> The body does not have a chance to break down all of these calories, and instead all of this excess fat is being stored. <S> In short, the beer alone does not cause the fat, it's the food that goes along with it. <A> Yes it does! <S> A beer belly is caused by excess calorie intake and reduced calorie expenditure because of a sedentary lifestyle. <S> Read in detail: http://healthmeup.com/news-weight-loss/the-truth-about-beer-belly-fat/5947 <A> Yes. <S> Also taking up several glasses of beer in a day can increase your blood pressure level. <S> People already suffering from high blood pressure are advised not to take in consumption at all. <S> https://www.addictionrehabcenters.com/addiction-treatment/inpatient-rehab/
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Most beer has a lot of calories.
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What is the German Beer Purity Law? I see some US beers advertising that they brew according to the "German Beer Purity Law." What is that, and is it still relevant today? <Q> It dates back to 1487, which is why you may notice the omission of yeast : it hadn't been recognized as an ingredient yet. <S> The law was removed from the books in 1993, and replaced by another similar law which allowed yeast, sugar, and some of the more common brewing ingredients. <S> In the case of a US brewery making such a claim, it's a sort of advertisement toward the "purity" of their product, i.e., they don't use adjuncts (rice, etc) or other flavorings (fruit, spices) in their beer. <A> In addition to what's been said, the original purpose of the order was to protect consumers from brewers who used problematic (toxic/psychoactive) herbs to preserve their beer, instead forcing them to use hops. <S> Also only using barley allowed wheat and rye to be used exclusively by bakers to keep the cost of bread down. <S> One could argue the tradition has kept German brewers from innovating, and also keeps a lot of interesting styles out of reach. <S> Most Belgian-style beers, despite having a similar heritage to German styles, will include candi sugar and spices like anise and coriander. <S> Technically, sour beers are also out. <S> Also, a lot of the Trappist ales will use sugar adjuncts. <S> Today, it's mostly a statement of adherence to tradition, which can carry good marketing weight. <S> But this is beer, not marketing. <A> The purity law has been introduced to regulate the production of beer in the Holy Roman Empire . <S> The original text stipulated that the only ingredients that could be used in the production of beer were water, barley and hops. <S> The "Reinheitsgebot" has actually survived the Holy Roman Empire. <S> Many German brewers are proud of this heritage and claim to stick to it. <S> It's relevance today is commercial.
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The German Beer Purity Law, also know as the Reinheitsgebot , dictates what ingredients may be used to create beer in Germany: barley, hops, and water. It's used as a label for marketing reasons.
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Can beer be recarbonated? I was perusing a question about uses for flat beer (" Are there any good uses for beer that has sat in my growler for too long? ") when I came across an answer that mentioned " any use that doesn't require it to be carbonated would be fitting ". If I have flat beer, and I have, say, a sodastream (or some such), can I effectively re-carbonate my beer? What would be the disadvantage to doing so? <Q> Sodastream: <S> maybe, but at your own risk. <S> According to Sodastream's FAQ , "You risk damaging your soda maker, not to mention making a big fizzy mess!". <S> However, there are a few articles discussing how to carbonate non-water with one. <S> Anecdotes vary: <S> It overpressurized and sprayed beer everywhere <S> It worked fine, but go slow Wild success! <S> Some tips: <S> It will definitely void your warranty Use plastic, not glass, bottles to avoid shrapnel if you make a mistake. <S> Take your time; most reports indicate it's easy to over-carbonate your beer. <A> Add sugar to bottle-conditioned beer <S> Warning : This method is error-prone, high-effort, and probably not worth your time. <S> Could be fun, though. <S> :) <S> Most commercial beer is force-carbonated . <S> That is to say, the beer is produced and ready to drink (minus the fizz) before they put it in the bottle and mechanically carbonate the beer. <S> The beer is intentionally left with a little of the yeast from the fermentation process, and is sealed with the sugar. <S> The yeast then does it's normal thing: it eats the sugar and excretes alcohol plus carbon-dioxide. <S> Since the bottle is sealed, the CO2 has nowhere to go, so it goes into dissolution in the beer, giving you that fizz. <S> Most bottled homebrew will be like this. <S> So, if you have a beer that is both flat and was bottle-conditioned (and therefore still has some yeast in it), you might be able to bottle-ferment it again: <S> Add a very small amount of sugar to the bottle. <S> Table sugar works, although corn sugar (which you can find from a brew store) is ideal. <S> It'll be really hard to get the right amount (about 0.083 oz), so I recommend pre-measured tablets of the stuff: http://www.northernbrewer.com/shop/munton-s-carb-tabs.html <S> Seal the bottle somehow. <S> If you have a bottle-capper and some caps, that'd be ideal. <S> Otherwise, you might be able to get by with a soda bottle and cap. <S> If you're really lucky, your beer is in a swing top bottle. <S> Wait a week, maybe a couple to be sure. <S> If you're lucky, there's enough viable yeast in the bottle to start acting again (now that it has new sugar to eat), which will create more CO2 and recarbonate the bottle. <A> Yes and No. <S> Yes you can re-carbonate beer either by injecting CO2 into it either with a Sodastream (are those things still around) or natural conditioning as mentioned in another answer. <S> No, you really don't want to do this. <S> If the beer has gone flat, it is likely that it has lost the protective layer from the CO2 and oxidation <S> has occurred and the beer is likely stale . <A> Yes, you can re-carbonate long flat beer. <S> If the beer has been only gone flat. <S> Once re-carbonated <S> I doubt that you would be able to tell the difference. <S> I did this once with Corni Kegs and a CO2 pressure system over a couple days for 10 gallons. <S> Tasted great. <S> Beer doesn't go stale without contamination, but will go flat without a seal to keep pressurized. <S> Next I am going to try to to rejuvenate a Growler from a microbrewery that I didn't screw the cap on tightly. <S> This time, however, I will be using 2 ltr bottles, baking soda and vinegar!
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Beer that is bottle-conditioned or bottle-fermented , however, is put into a bottle with some extra sugar.
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What food pairs well with an IPA? Consider your average american IPA. What food would go well with it? <Q> As a complete novice to food pairings with beer, I've been looking at this nifty pairing chart on http://www.craftbeer.com <S> [PDF] whenever pairing questions have come up on Beer. <S> SE. <S> According to it, the suggested pairing for an IPA is Strong, spicy food (classic with curry!); bold, sweet desserts like carrot cake and for a Double/Imperial IPA is Smoked beef brisket, grilled lamb; Southern chicken-fried steak. <S> I found a great little summary by Michael Agnew (2012) that explains some of the rationale behind these pairings (emphasis mine hereon): <S> When pairing IPA with food you have three basic flavor hooks at your disposal; bitterness, hop flavor (spicy, grassy, herbal, earthy, and citrus), and caramel. <S> Hop flavors have a great affinity for spices and light fruits. <S> Bitterness has a cooling affect. <S> Paired with spicy dishes , IPA will fan the flames at first, but douse them in the end. <S> Bitterness also amplifies salty and umami flavors . <S> The caramel flavors in the beer will latch onto the sweeter side of a dish, tying into things like caramelized onion or the crispy skins of roast poultry. <S> And the hop acids and carbonation make IPAs great palate cleansers to take on even the fattiest deep-fried delights. <S> Samuel Adams has a "Pair with Sam" tool, and looking at its suggested pairings for their Whitewater IPA (hoppier than their Latitude 48 IPA), pork appears to be the meat of choice: pulled pork, barbeque ribs, chorizo, roasted pork tenderloin, and sweet sausage ; and the rest of its suggestions align with the salty-and-spicy pattern we've seen. <S> We seem to have found strong consensus already, but just one more to make sure. <S> Actually, I think they stole those words from Wegmans' Guide to Beer and Food Pairing . <A> CHEESE! <S> Extremely sharp cheddar is best. <S> My personal favorite is Tillamook Special Reserve Extra Sharp. <A> Cured meats - the saltiness of the meat and bitterness in the IPA play well together. <A> Spicy foods. <S> My personal favorite is stir fry. <S> Something that isn't heavy on carbs is ideal, so with stir fry I go light on the noodles (or rice) and heavy on peppers, onions, and meat (usually chicken or beef). <S> Again, don't use the milder sauces like teriyaki, use something with some kick. <A> Be mindful of the variety of IPA on the US market -- the average New England IPA is a different beast than the average west coast IPA. <S> I'll call out a few excerpts from the serious eats article Andrew Cheong quotes above: IPAs <S> that lean extra-heavily on bitterness can be a bit tricky to match with food, which can make the beer seem astringent. <S> ... <S> ... <S> IPAs that emphasize hop flavor and aroma over bitterness... <S> I especially like these beers when served with Indian food. <S> Hop flavor melds wonderfully with common Indian spices like tamarind, coriander, and cardamom. <S> ... <S> Mexican food mixes light and dark flavors like cilantro and refried beans, lime and roasted chilies. <S> Those combinations make great partners for IPA with its own caramel/citrus combo. <S> Stick with lighter-bodied beers here, since bigger brews can easily overwhelm. <S> But that was likely an exceptionally high-IBU beer. <S> (I suddenly feel the need to gather more data).
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In Blue Point Brewing Company's words , its IPA pairings are meant to complement intensely flavorful, highly spiced dishes, such as curry, and bold, sweet desserts like flourless chocolate cake and crème brulée or rich, aromatic, spicy and smoked foods such as chili, BBQ ribs, grilled chicken, and beef. A sharp Vermont or New York white cheddar will do as well. My personal experience -- I predominantly drink IPA these days -- is that I haven't had a memorably bad pairing, save for once where an overly sweet cupcake clashed with the bitterness of the IPA.
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What constitutes a Pale Ale? I ask this because I just ordered an "American Pale Ale" and it's actually quite dark in color. So how can I tell a pale ale? What actually defines an ale as pale ? <Q> It's historical. <S> The "Pale" in Pale Ale is mostly historical. <S> In the 18th century, most beers were dark due to being produced with barley malt that was kilned or roasted over wood fires. <S> But from England emerged a new technique using pale malts , cured in coke-fuelled kilns . <S> This applied to both ales and lagers, resulting in beers that were bronze, copper or gold—and while you wouldn't look at such colors today and consider them notably "pale," they certainly were pale in contrast to beers back then. <S> In the turn of the 19th century and beyond, the style spread from England to the rest of Europe— <S> When a new brewery was built in Pilsen in Bohemia in 1842, a coke-fired kiln was imported from England. <S> The result was the first golden lager, Pilsner Urquell, which was made possible by British ingenuity and technical advance. <S> http://www.beer-pages.com/protz/features/ipa.htm <S> Note that American Pales are distinct from India Pales as well as from American India Pales. <S> See my answer about the differences between styles of IPAs . <A> The American Pale Ale (also known as APA) is normally a light-colored ale that is traditionally hoppy with light malt flavor. <S> But its formal description is a little bit more flexible. <S> It's defined as a very balanced style. <S> It originates from the English Pale Ales. <S> The BJCP describes it as the following (short version): <S> Aroma : <S> Moderate to strong hop. <S> Citrusy hop is very common. <S> Also, low to moderate maltiness. <S> Appearance : Pale golden to deep amber. <S> Generally quite clear. <S> Taste : Pretty much the same as aroma. <S> Mouthfeel : Medium-light to medium-full body. <S> For more information see here ! <A> Brewers often add additional malts in order to achieve whatever it is that they're specifically trying to achieve for a given beer, and a pale ale with some caramel or crystal malt will indeed have a darker coloration though on the whole <S> the properties of the beer may still mean that it resides within the definition of the pale ale style.
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A pale ale is traditionally an ale that is is brewed predominantly with pale malt and is hop forward. Moderately large white to off-white head with good retention.
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Why is it important to have foam on a beer? I've seen people complain when served a beer without foam. Equally, getting a glass full of foam is no use. When serving a beer, how much is the right amount of foam and why is this important? <Q> Most importantly, a good head helps release the aromas of the beer, especially the hops. <S> Aroma is everything for enjoyment of a good brew. <S> When enjoying a super-hoppy IPA, you should always use a glass that provides a large surface area for aromatics to rise from. <S> Stouts definitely benefit from a thick, silky head. <S> And lastly, it's eye candy. <S> As for the right amount of head, it varies. <S> Generally in an average pint glass you want 1-2 finger-widths of head. <S> Some hefeweizens and wit beers are best with a bit more. <A> Apart from the simple explanation of people liking the foam, the lack of head could indicate problems with the beer. <S> For example: It could mean that the glass is dirty, or there is left over soap residue on the glass. <S> This can affect the taste of the beer. <S> It could indicate that the beer has lost its carbonation (the head being formed by the gas quickly coming out of solution in the beer). <S> For many forms of storage a lack of internal pressure will indicate that they are no longer sealed properly, which makes it easier for infections to enter the beer or for it to oxidise. <A> One of the most important tasks of the foam is to protect the beer against oxidation. <S> This is why some beer glasses have a rough patch at the bottom so the bubbles will have place to "sprout" from. <S> In a Duvel glass for instance it is a laser engraved Gothic "D". <S> When the beer is in the glass (Duvel is highly carbonated) you can see the bubbles rising from the rough spot and creating a protective blanket on the beer, thus preserving the taste long after you poured it. <A> Here in the Netherlands, we mostly drink poured beer with like 1/4 of the glass filled with foam <S> and we think the beer is not as good anymore when there is no foam in it as the carbonation is gone. <S> But I don't know how it is in other countries, so I believe it is beer and country-specific <S> how much foam there is in a glass. <A> I must say that before starting to brew myself I disliked the head, but when you start to deal with low carbonated beer, it becomes interesting. <S> Just bought this weird "head maker" an ultra-beer thing it is really weird, looks like a sex toy, but creates head with ultrasound. <S> Just stick it in the beer and press the bottom. <S> With some beers it definitely adds flavor, especially hoppy beers.
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As for the ideal amount of head, to some extent it will depend on the style of beer. It can also provide the a pleasant mouth feel.
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What do these "OG" and "RDF" numbers mean? I recently got a "Gnarly Oak" craft brew package. Three 22 oz beers and a glass. However, on the beers are some abbreviations and numbers I don't understand. they all have a 5.5% ABV, and I get the IBU and color numbers but what are the rest? The numbers and abbr's are below: Winter Bock - 15 OG, 62.5 RDF - light, tasty, ever so slightly bitter Hazelnut Dark - 15 OG, 60.4 RDF - nice bitter red with slightly sweet aftertaste Chocolate Stout - 14.8 OG, 66.8 RDF - very sweet with hints of chocolate and malt EDIT In light of the answers so far, I should say I have brewed my own, and if OG is original gravity, it doesn't fit with the scale I know of. if 15 OG ~= 1.015, it doesn't match what that would give in final ABV. Is this OG on a different scale I haven't seen <Q> From the figures you posted, OG - "Original Gravity". <S> When measured with a hydrometer, it measures the density relative to water. <S> E.g. 1.010 is 1% heavier than water. <S> The units here are degrees <S> Plato (°P), which describe the amount of dissolved sugars. <S> Here, 15 means 15% dissolved sugar. <S> This means the beer (or more correctly, the wort ) contained 15% sugar before fermentation started. <S> RDF - The real degree of fermentation. <S> This is in contrast to the Apparent Degree of Fermentation, which is (OG-FG)/OG. <S> When the final gravity is measured using hydrometer, the alcohol in the beer, being less dense than water ( SG. 0.789 ) causes the gravity to appear lower, so it looks as though the yeast has fermented more sugar than it actually has. <S> The Real degree of Fermentation takes the alcohol into account and computes the actual amount of sugars fermented. <S> This tells you the how much of the original sugar was fermented (as a percentage). <S> So, what does this mean in practice? <S> Winter Bock - 15 <S> OG, 62.5 RDF - light, tasty, ever so slightly bitter <S> This has an average RDF for a beer that size, so it will be somewhat malty, but not cloying. <S> Hazelnut Dark - 15 OG, 60.4 RDF - nice bitter red with slightly sweet aftertaste <S> This has more dissolved sugars in it compared to the Bock, so you'd expect it to be a thicker mouthfeel and slightly more sweet, although you may not taste the sweetness if it's offset by roasted malts. <S> Chocolate Stout - 14.8 OG, 66.8 RDF - very sweet with hints of chocolate and malt <S> Being the driest of all the beers, yet the taste description is given as very sweet. <S> This shows that knowing the residual sugars doesn't tell you the sweetness, simply because there are different kinds of residual sugar. <S> For example, dextrins create body, but have relatively little taste, so would taste not as sweet as a beer containing a lot of residual maltose or glucose. <A> I'll answer one half and leave the other half to someone else. <S> is a measure of the density of a liquid. <S> Since its is mostly water, you can compare beer’s density to water to find out how much other stuff is in it. <S> Water has a gravity of 1.000, and beers will often have an original gravity of 1.200 to 1.020. <S> “Original Gravity” is the density of beer before it’s fermented (when it’s called ‘wort’), and “Final Gravity” is the density after it’s fermented. <S> You can determine the alcohol content of a beer by comparing the two gravities and inferring how much fermentable “stuff” disappeared during fermentation (i.e., was converted to alcohol and CO2). <S> In commercial beer, you can use OG as a shorthand for how “Big” the beer is because it indicates how much malt and other fermentable stuff was in it. <S> So a lighter-flavored beer like a blonde or a pilnser will often have a low original gravity (1.020 to 1.050, for example), whereas a big stout or barelywine might have a higher original gravity (1.080 up to as much as 1.200). <S> OG is in important measurement for home brewers, <S> so another use of it on a commercial beer is to help people produce clones of said beer at home by reproducing the OG (among other factors). <S> Definition <S> To get a little more technical, Specific Gravity is the ratio of the density of one liquid to another. <S> In brewing, we always use water. <S> So, the density of water divided by the density of water is 1.000. <S> The density of beer divided by the density of water is what we refer to as ‘gravity’ when discussing beer. <S> And since it’s a ratio of two identical measures, there are no units. <S> It’s not 1.000 somethings; it’s just 1.000. <S> Plato Homebrewers often use "brewer's points" (eg 1.123), but you'll sometimes see the "Plato Scale", which is more popular in central Europe. <S> A good approximation is that 1˚ plato = 4 brewer's points. <S> So 12˚ Plato corresponds to a gravity of 1.048. <A> OG = Original Gravity <S> The amount of sugar available for fermentation, measured based on density vs water (1.000) <S> More residual sugar == more sweetness <A> OG stands for "original gravity", which is the density of the liquid, before fermentation in the case of beer. <S> Another "gravity" you may hear is "final gravity", or FG: <S> the density of the beer after fermentation. <S> Typically, gravity is expressed as thousandths over 1.0, where 1.0 is water. <S> However, Gnarly Oak says that their Winter Bock has an OG of 15, which is likely in degrees Plato. <S> I leave it to other answers to thoroughly explain what that is. <S> The density, of course, is increased by the sugar and other "good stuff" that makes beer, well, beer. <S> After the yeast has eaten the sugar and produced alcohol, you can measure the final gravity. <S> What makes this interesting is that if you have the OG and the FG, you can calculate your alcohol by volume with a little math . <S> I am completely unfamiliar with RDF, however.
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RDF = Real Degree of Fermentation sugar in cold wort has been fermented into alcohol in beer with the term degree of fermentation. OG is “Original Gravity” Specific Gravity (often shorted to just ‘gravity’)
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Do cans change the taste of beer? My favorite beers come in bottles and in cans. I always buy it in bottles because I've heard that cans negatively impact the flavor of the beer. Is this true? If so, how does it work? <Q> First, I love this question because it is actually interesting. <S> I researched this when I noticed that bottled coke tasted so much better than canned coke. <S> Cans keep out all light so the contents actually never become tainted. <S> The reason that most like bottled over canned is because they like the taste with those impurities. <S> Some complain that they can taste aluminum with cans, but this is more than likely in their head since cans are lined with a thin layer of plastic. <S> I like certain beers better in cans and certain ones better in bottles. <S> I would try both :) <A> As a member of a Studentenverbindung, having one principle of scientia, we of course tested this a long time ago with around a dozen or maybe a bit more testers. <S> We poured beer from the same manufacturer (fresh batch) into glasses and had people taste them, and for every glass (everyone had multiple ones) they had to say if they think it was from a bottle, a can, or a keg, and which tasted better. <S> After around 50 or 60 glasses, there was no statistical evidence whatsoever that any of the three could be identified, or tasted better. <S> From my personal experience though, I always think that a keg is better than a bottle is better than a can. <S> But why is that so? <S> I only have the theory that due to the feeling of the container you drink from, your taste is altered (just like food with the same flavour/taste somehow tastes different, with a different texture). <S> Additionally I think the amount of beer that flows into your mouth is different, as well as maybe the turbulence, causing a different amount of carbon dioxide (or nitrogen, depending on your beer culture) to leave the beer before you can actually taste and swallow (which again changes the texture). <A> I heard a quote from the revered Charlie Bamforth , who basically said that packaging beers in cans was a far better way to preserve the beer from brewery to customer than packaging in bottles, but bottles are still more aesthetically pleasing to the customer, so they are usually preferred. <S> And that's from a man that has been head of Quality Assurance for a number of years. <S> It's purely in the mind - there isn't any real change to the beer. <S> If anything, the difference with bottled beer is that the canned version is better preserved. <A> I think that the real difference is going to be between keg beer and can/bottle beer. <S> Canned/bottled beer has a longer shelf life than keg beer. <S> Canned/bottled beer has a shelf life of roughly 45-60 days, whereas a keg is only 25-40 days 1 . <S> This means that worst case scenario for comparison you could be tasting a 2 month old canned beer versus a 3 week old draft. <S> It can cause a difference in taste, there is a "freshness date" after all. <S> (See this excellent answer from @mdma for more information on what happens as beer ages ) <S> But where does this date come from? <S> Almost all imported retail beer is pasteurized. <S> The reason for pasteurizing the beer is from a business standpoint. <S> It basically allows the beer to last longer and be shipped at room temperature (this applies to kegs, cans, and bottles). <S> An alternative to the pasteurization process is bottle conditioning. <S> Most domestic beers follow this path. <S> Essentially this process involves beers being sterile filtered and chilled to the point that any surviving bacteria, which could ferment the beer, become dormant 2 . <S> So basically the probability that the beer begins to ferment is higher over time. <S> A canned beer and a keg beer can taste the same if they both left the brewery at the same time, and both experienced the same conditions during the time it took them to reach you. <S> It is just that kegs have a better chance of taking less time and of being better preserved. <S> From a practical standpoint though, bottles can cause broken glass, kegs weigh close to 50 lbs. <S> full, and cans allow for shotgunning. <S> 1. <S> How long will a keg of draft beer remain fresh? <S> 2. <S> What is pasteurized and non-pasteurized keg beer? <A> I don't know how/if the actual storage in cans vs bottles affects the taste, however you should expect that they are not filled with the same beer. <S> Many companies will have different production logistics, and the can will often come from a different site than a bottle of the same brand, and will have slightly different water and production process, so the beers will taste slightly different before they even touch the can; and they may even have intentionally different production and additives. <A> If you are drinking beer directly from the can or bottle, then one measurable difference is the speed at which it warms up while you are drinking it. <S> As glass is an insulator and aluminium is a conductor, you'd expect the can to be more efficient at transferring heat from your hand and the environment into the beer. <S> So a glass bottle should keep the within the optimum temperature range for longer than the can. <S> This result is backed up by some research done by students at Worcester Polytechnic Institute , which compared the rate at which refrigerated liquid warms up to room temperature in glass and aluminium bottles. <S> The heating rate differences should be even more noticeable if the bottles were in contact with a body temperature heat source. <S> This effect can be minimised by insulating the can using a stubby holder/beer cozy. <S> In another experiment comparing cans held in a person's hand , over a 30 minute period an uninsulated can rose in temperature by about 14°C while the insulated can rose only 3°C.
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I actually do not think that the can itself changes the taste of the beer as much as the beer placed in the can may be a little different. Make sure your container of choice fits your environment :)
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Are Spittoons Used in Beer Tastings? When tasting wine, it is often suggested that tasters do not swallow the wine, but simply taste as necessary and then spit into a bucket/spittoon of some sort. This, of course, aids in the tasting of large amounts of wine without the effect of the alcohol (getting drunk). In casual tastings among friends, part of the fun is obviously getting drunk. However, I've been wondering if judges at competitions or more formal tasting venues (possibly breweries themselves) use spittoons. To put it in the form of a question: Are spittoons ever used for beer tasting? <Q> To my knowledge, the answer is always no . <S> To fully experience the flavor of beer, one must swallow it. <S> This is because, unlike the vast majority of wine, beer is carbonated (albeit to varying degrees). <S> When you swallow beer, some of the carbonation escapes the liquid as gas, and actually rises up from your throat into your nose (or, at least, into your nasal passages), carrying with it some of the flavor molecules of the beer. <S> Thus your sense of smell combines with your sense of taste to produce an overall sense of flavor in a manner that is different from what occurs when you drink (uncarbonated) wine. <S> If you spit out your beer, you're ruining the experience. <S> (This explanation is based on one that I heard years ago from a brewmaster at Anheuser-Busch. <S> I can't remember his exact words, but you get the gist.) <S> On a side note, regarding the important relationship between taste and smell, I'm sure you will see tasters at both beer tastings and especially wine tastings swirl their drink a bit to smell it from the glass before tasting it. <S> The difference is that carbonated beverages pack a smell double-whammy coming at you after you swallow. <A> Not generally. <S> The aftertaste of beer is more important than it is in wine, and much of the aftertaste comes from swallowing. <S> Also, beer isn't generally as alcoholic as wine, so the risk of getting drunk on a taste is lower. <S> Although some beers can be in the 10-12% range, the average abv is much lower. <S> Further, although the idea of a tongue map has been relatively discredited in scientific circles, it was taught in schools for a long time. <S> As such, many people (including beer judges) incorrectly believe you taste bitterness with the back of your tongue. <S> Since bitterness is a much larger part of beer than wine, many believe you need to swallow to properly taste it. <A> Spitoon? <S> No. <S> Bucket for dumping the remainder? <S> Yes. <S> I agree with the other posters, with the addition that in the ONE competition I've judged in as a Novice, <S> as Sloleam points out, we typically did not finish the 2-3 oz or <S> so that was poured, and the remainder was dumped in a bucket. <S> According to the BJCP guidelines , you sniff it, look at it, taste it (allowing it to linger before swallowing). <S> That's it. <S> After that, you typically dump the rest in a bucket, especially if you are going to be judging several categories :) <A> No. <S> While in a wine tasting it's acceptable to spit out the wine, in beer tasting you actually have to drink the beer. <S> Keep in mind that while judging beers at a tasting you only get ~2 ounces, so <S> it's easier to pace yourself and dump out anything past what you need to get your impression. <S> Half of beer judge training is learning to quickly assess flavor.
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I don't remember the exact reasoning since it's been a few years since my Beers of the World class, but I think it had something to do with the carbonation affecting the after taste if you don't swallow the beer.
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Should bottle conditioned beers be consumed quickly after purchase and do they carry on changing taste for a while? Just wondering how a bottle conditioned beer will change over its life - if at all? And is there a perfect time to drink one? Also do different types change differently? <Q> Quite the opposite, bottle conditioned beer is perfect for aging. <S> The yeast carbonates the beer and will produce slight changes over time, like upping the ABV. <S> This needs to be done in climate controlled environments similar to wine. <S> The yeast will settle to bottom and you want to avoid pouring this into your glass when finished. <S> I brewed a Imperial honey stout and aged a few bottles at 68f for about a year for my birthday. <S> The beer started at about 7.2 ABV <S> The beer finished at over 9 ABV (this is because the yeast had plenty of starch to munch on and the carbonation was not affected. <A> In addition to Waitkus his answer I would like to note that the perfect time to drink a beer depends on the type, brand and most importantly taste. <S> There is also a difference when storing larger bottles. <S> For instance a 75 cl Duvel bottle (or larger) can be stored easily for several years, whereas the smaller bottles of the same beer don't fair too well. <S> Other beers, mostly heavier abbey beers allow for prolonged storing. <S> For instance an Orval changes taste quite drastically once you have stored it for about 1 - 2 years. <S> I've even seen these beers being stored for 30 years and still being drinkable (although you needed to pour it very carefully as there was a lot of cediment). <S> The monks of Westmalle even have 35 year old beer on site for their own consumption. <S> They also loose a bit of their carbonation (very old beers). <A> Bottle conditioned beers definitely have longer shelf-lives than their pasteurized/filtered counterparts - the yeast helps scavenge oxygen and release sulphites to stop free radicals (such as from lipid breakdown) from staling the beer. <S> The yeast can survive for decades - Guinness observed yeast still alive in the bottle after 35 years! <S> While a light beer may be best consumed within 5 years, darker beers can be aged much longer than that. <S> See bottle aging beers - do's and don'ts
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How long a bottle conditioned beer can be aged for and, thus how soon you should drink, comes mainly down to the alcohol percentage - stronger beers age better, and the color - darker beers age better than lighter ones In regards to taste, they tend to become heavier, stronger in taste, sometimes a bit more sour.
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