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Why do cargo aircraft still have floors? Even with dedicated cargo aircraft built as cargo aircraft (rather than converted from a passenger-carrying configuration), the cabin is virtually always still divided into an upper and a lower lobe (which would, on a passenger aircraft, be the passenger cabin and the cargo ho...	On most transport aircraft the floor structure, especially the beams along the sides, is a key part of the fuselage as a load bearing pipe whos lower half is under compression and benefits from the stiffening.
why are turboprop/turboshaft engines rated only in horsepower and never in ft-lbs of torque like diesel engines or electric motors? I realize torque and horsepower are essentially the same measurement since horsepower is simply torque over time. But I'm curious as to why diesel engines or electric motors always provide...	The reason a Diesel engine has a torque figure and a horsepower power figure is because max torque and max horsepower occur at different engine RPMs.
Can the CG move out of bounds as fuel is used? I've never bothered to check the weight and balance when the tanks are empty. I always assume that if the Center of Gravity is within range when the tanks are full, then it will remain within range as the flight progresses. Am I correct? Should I compute the W&B on both e...	On swept wing airplanes with a center tank, the center tank is almost always burned first and it causes an aft shift of C of G as its fuel is burned, followed by a forward shift as the wings are consumed. Bottom line is, do whatever the weight and balance chart for the airplane says to do.
Why should autofeather only be used for take off on the Dash-8 Q400? The Bombardier Dash-8 Q400 FCOM says (emphasis mine): The autofeather system provides automatically initiated propeller feathering following an engine failure during take-off, and power uptrim of the operating engine (Figure 12.22-5). Autofeather i...	There is no point to use autofeather when there is no great benefit of that because: Multiplying the phases where you rely on it, is multiplying the risk to forget it armed, and this feature being forgotten has been a source of incidents that could have turned into dramatic accidents.
Why did narrowbody jetliners take so long to switch over to high-bypass engines? High-bypass turbofans were introduced into the airliner market around 1970, when the first widebody jetliners were released (the 747 was first, followed in rapid succession by the DC-10, L-1011, and A300); however, narrowbodies continued t...	Early high-bypass engines were expensive and unreliable.
How is the change of moment handled in a Weight and Balance calculation with a swept wing aircraft? I'm writing a weight and balance calculator for a charter operation. Every aircraft I've ever flight planned for has all the tanks on the same moment arm, so I don't know how you calculate the W&B for an aircraft that h...	The manufacturer's weights engineering group will determine the overall fuel load's center of gravity moment for different fuel volumes and plot the results on a chart as a curve.
Can longer paths consume less fuel than the (shorter) great circle path? Is the most fuel-efficient route between points A and B always along a great circle ? Although somewhat counter-intuitive, this comment on an aviation blog seems to suggest that longer paths ( in terms of geographic distance covered ) can save ...	The hard answer is no, the most fuel efficient route is the one that has the aircraft in the air for the shortest amount of time.
Can I fly through these military airfields' class C airspace? I am a low time private pilot now based in Pensacola. I’m a bit unsure how the Class C of PNS/NAS Whiting Field is handled. As you can see they all overlap. PNS is a civilian field while the others are military. If I was going to fly VFR to the northeast, ca...	If the military airfield does not want civilian aircraft to cross the field for any reason approach control will direct you around it.
From which rating would it be easier to transition to an Osprey? Fixed-wing or rotary-wing? If the future of flight was to be on aircraft that were a hybrid of fixed-wing and rotary-wing (for example the Osprey), assuming they had similar technical abilities and the same number of flight hours, who would have an easier...	The rotary wing physical skill set is so much more demanding than the fixed wing one.
What are the areas of an aircraft that suffers most from G forces? i want to ask this time as to "what are the areas of an aircraft that feels or suffers the most from G forces?". i am asking this in terms of structural design and physical limits of the pilot(the position and seat angle) and the plane.please try not to...	Basically 3 places on an airplane see very high concentrations of stress in a small area from in-flight G loads.
Can ATC terminate flight following AND approve (arbitrary) frequency change while still inside Class C airspace? Unusual (for me) event inside Class C. Can ATC terminate flight following inside Class C and approve frequency change. Background: Requested and received VFR FF at 6500 msl prior to approaching ONT Class C ...	The answer is they can, and just because they do, does not change the regulations.
How can I use an ADS-B receiver to make my aircraft visible in Flightradar24? I recently bought a SENTRY ADS-B receiver for the aircraft in order to track the flight. How could I make Flightradar24 or Flightaware show my aircraft and how to register my aircraft on the website? <Q> ADS-B is broadcasted by many aircraft...	For FR24, FA and other flight tracking websites to "see" your aircraft, it will need to have a Mode S transponder (or UAT transmitter if in the US) with ADS-B "Out" installed.
What would happen if I exceeded mach 1 over a regulated area? What would happen if I exceeded mach 1 over a regulated area? Are there any penalties in place for this violation? Would ATC actually know I’m flying supersonic or would they have to go out of their way to check my groundspeed and work out my approximate ...	ATC radar wouldn't catch it, since they see ground speed and know neither your head/tail wind component nor the exact temperature at your altitude (which determines the speed of sound). Depending on the place and altitudes this took place at, the FAA would certainly cite you on 91.817 and 91.13 careless and reckless op...
Why are the leading edges of wings not always made as 'sharp' as possible? Why is an airplane's wing (the leading edge) not made as sharp as possible to break the air, in the same way that a ship's hull is made sharp to easily break the water? This is unlike Concorde's nose and most jet fighters' noses, which are made...	Simplifying the physics a lot, you can imagine that before a round leading edge, an additional “wedge” † of only slightly higher-pressure air is built up, which can divert the flow around the wing almost as efficiently as a sharp edge would.
Can pilots choose runway and landing direction? Pilots normally receive landing clearance for a specific runway assigned by ATC . Absent an emergency , can pilots of commercial flights (depending on the wind conditions for example) choose a different runway the landing direction for this runway or both ? If no,...	Normally, you use the runway assigned by the controller, unless you have a reason to use another one.
What’s the setting range altimeters can handle? What’s the setting range altimeters can handle? Is there a standard requiring a certain range for aircraft to be certified? Are there many occasions where a QNH is so high or low that airplanes have problems handling that? <Q> The stand-alone altimeters in older aircraft ...	There are actually multiple different answers depending on the specific type of altimeter system and what standard applies.
Disadvantages of using thrust vectoring only in an aircraft with variable rotation nacelles such as the X-19 Take a quad tilt rotor aircraft such as the curtiss-wright X-19 or even a bi-tilt aircraft such as the V-22. What would be the advantages or disadvantages of using thrust vectoring only for control of roll, pit...	There are simply no propulsion systems that would be as reliable. The advantages: Short/Vertical takeoff.
Can a bird strike destroy the stealth capability of F-35? There is a video according to which a F-35 aircraft has been struck by a bird in Israel. This, allegedly, disabled its stealth capability. More than a year earlier, two storks allegedly damaged another F-35 and made "maintenance work" necessary. Can a bi...	Birdstrike can puncture holes in airframes, shatter canopies, damage engines and wreak all kinds of havoc.
How is the effect of wind on arrival time handled? If a commercial plane encounters strong tailwinds, would the pilots set the autopilot for a fixed arrival time (if that is possible), or would it be ok to arrive way ahead of schedule? I imagine this could disturb airport operations, and that there are fuel economy c...	One thing you can be certain of is that the airline itself will not on its own accord do anything to increase its fuel burn just to avoid arriving early; only if ATC forces it to.
How can I know DME distance? When I fly 12000ft, how can I know a distance from DME station?Is there any formula to know or measure distance from DEM? <Q> If your radio has DME installed, then it is shown on the instruments <A> Just to be clear, when you are asked for your DME from a station or using a DME fix, what is...	If you are asking for a lateral distance, that could be done using simple trigonometry taking the slant distance and field elevation of the DME station, and aircraft altitude to compute an azimuth from the station, thence a lateral offset can be computed.
Would there be a purpose for a set of compressors in an electric turbo fan? This is actually a two part question. Would there be a purpose to a compressor in an electric turbofan where there is no need for a combustion chamber, and if not, is there then a purpose for a bypass as well? Sorry if I'm unclear, as i am not...	The only purpose of the compressor is to provide high pressure air for the combustion chamber and turbine.
Is the MD-11's third engine slightly nose up? From my visual inspection, the third engine (the engine on the horizontal stabilizer) is slightly "nose up", especially compared to the engines on the wing. That means, the front part of the engine is lifted slightly. Am I correct? If yes, what is the intention? <Q> Yes, th...	It may be for the same reason down thrust angle is commonly put into tractor engine mounts - to compensate for pitch up tendency of air craft as they accelerate from added thrust leading to increased velocity.
What is the maximum angle between an airplane and runway centerline when touching down at a crab angle in a crosswind landing? What is the maximum angle between the airplane's heading to the runway when an airplane is being landing sideway due to crosswind? <Q> A B777 (as in your photo) would generally have a maximum c...	There isn't a maximum crab angle (you aren't supposed to touch down crabbed to the extent you can prevent it) and there usually isn't a maximum crosswind component either on most airplanes as a "legal" limitation.
Is a mode C transponder required underneath Class C airspace? FAR 91.215 states that a mode C transponder is required for... all aircraft in all airspace above the ceiling and within the lateral boundaries of a Class B or Class C airspace area designated for an airport upward to 10,000 feet MSL My flight instru...	You do not need a transponder to operate under Class C airspace if there are no other overlapping airspace areas where a transponder is required.
Why is this video of a G36 Bonanza taking off so scary? Why is this video of a G36 Bonanza so 'scary'? If they had clipped the top of the trees, would it really have brought the plane down? (And even if yes, it looks pretty survivable). <Q> Because those trees will kill them <S> If you look at this document re...	Had a pilot collided with the treestops at the end of the runway, there was a good chance that he would have lost control and crashed.
Why do we say certain things three times (e.g., "Mayday, Mayday, Mayday"), rather than two or four? Repetition is a key characteristic of communication in the control tower, cockpit, and control room. Some phrases, like "Mayday" get repeated. The speaker says the same thing three times. We know this is for redundancy....	Procedure calls for the mayday distress signal to be said three times in a row so that it won't be mistaken for another word or phrase that sounds similar under noisy conditions.
Why not make the touchdown zone of runways wider than the rest? Reasons: Save money by making the rest of the runway narrower Larger margin of error left and right Easier to turn around, if necessary And if the reason that it isn't done is merely for regulation/legal reasons: Is this something that would be pract...	Because planes that landed towards the edge of the touch-down zone would run off the side of the runway when it narrowed.
Can horizontal stabilizer trim be worked independently (each side)? I notice most jetliners have a big trim wheel on each side of the center console. This wheel is black with white stripes, and notably turns on its own via the autopilot. Two large trim wheels: And obviously, most jetliners have two horizontal stabil...	Splitting the stabilizer would be structurally dangerous if one side is controlled while the other is fixed.
How much clearance is provided when taking off over a 50 foot obstacle? When performing a takeoff over a 50' obstacle, how much clearance is provided between the obstacle and the aircraft and where can that be found? <Q> Calculated figures for take-off distance required (TODR) are to only just clear a 50-foot obstacl...	The distance provided is what the airplane can do.
Would a flight consisting of solely first-class passengers be cancelled due to center-of-gravity issues? Consider any modern jetliner (narrow-body and widebody separately) in a standard 2 or 3 class configuration. If somehow only first-class or business-class passengers bought seats, would that plane be impossible to f...	As has been noted in the previous answer and comments to date, you can compensate (if you need to) for a first class loaded with pax but with the rest of the cabin empty by putting the pax bags in the rear.
Why didn’t the Captain of Cathay Pacific flight 780 shut down engine 1 and land with a more reasonable speed? In the approach phase, engine 1 of Cathay Pacific flight 780 got stuck at about 70% N1 and it forced the crew to do an overspeed landing (230knots). Why didn't they shut it off by turning the fuel pumps off?...	I could be wrong but reverse thrust from the running engine helped to stop the plane 1 as it was approaching at a great speed way over the recommended landing speed, so shutting the running engine off right at approach would have made the plane to overshoot the runway, making the situation worse.
Why do carburetors tend to produce richer mixture at higher altitude? The pressure drop in the venturi is proportional to air density and the fuel is at ambient pressure in the float chamber, so I would expect the fuel flow to reduce proportionally with density, and that response to preserve the fuel-air ratio over cha...	There is air in the bowl, sure, and as that air pressure decreases with altitude there is a bit of a decrease in the pressure behind the fuel, however the part you may be missing is that air can mix with a much higher ratio of fuel than what is ideal for an engine.
Why do heavy departures wait 5-10 minutes on the runway at ZRH? I'm frequently travelling to Zürich for business and I usually make my schedule so that I have at least an hour to do some planespotting and photographing at the ZRH airport. Whenever I came to the airport, the runway usage was the same: RWY14 for all the...	In addition, smaller aircraft departing from runway 28 would have a required delay after a large aircraft departing from runway 16, due to wake turbulence.
Do any airports have runways or taxiways that cross active rail lines at grade? Gibraltar has a runway which crosses an active road at grade (which, due to the peninsula’s geography and the resulting constraints on the airport’s location, happens to be the main road connecting Spain and Gibraltar, thus bringing traffi...	Their is a lightly used freight line crossing the runway at Filton airport, Bristol, UK.
Does the movement of the magnetic poles affect aviation? Recently I read that Earth's magnetic pole moves quite significantly, several kilometers. Do these changes affect aviation, i.e. for pilots landing their airplanes? <Q> I don't think magnetic shifting affects the pilots directly, but it does force airports to re-...	While the position of the pole does wander by a bit, this doesn't cause major problems for aviation for several reasons.
Is 'bouncing' an airliner on landing in high winds a deliberate technique, or something always unexpected? Last week, 767 landing at Newark, high winds, a good deal of rocking in the last few minutes, some passengers quite distressed. The landing was harder and noisier than usual, and we immediately floated upwards, mu...	The reason an aircraft "bounces" on touch down is that it is going too fast to "settle" on the runway.
What vertical separation is required in a holding stack to avoid wake turbulence? Sometimes in my free time I play Endless ATC, a game where one acts as the approach and departure controller. In the game (as in real life) the controller is forced to put planes in a holding stack, separated vertically by 1000 feet. Is...	But the answer to your question remains the same: the vertical separation to be applied in a holding stack (below FL290 and during RVSM) is 1000 feet. In countries where Reduced Vertical Separation Minima (RVSM) has not been implemented, 2000 feet of vertical separation is required above FL290. 1000 feet is not enough ...
Can a turbofan run without the fan to provide power without thrust? Is it possible for a turbofan jet - like on a 747 - to run without the fan, if for example you just want the thrust from the internal jet to use to heat up water, not to use as thrust? <Q> No , the fan is directly connected to the outer compressor and ...	A turbofan without the fan would be called a turboshaft engine .
On the 737NG, after deployment of spoilers automatically after landing, do the spoilers automatically go back down? So, I was just wondering whether the spoilers on a 737-800, after automatic deployment when landing, will go back down automatically, or need manual input by pilots for the spoilers to go down. <Q> The sp...	There is usually a timer cycle of say 30 or 40 seconds after deployment, while still on the ground, at which point they retract and disarm.
How to reverse course when there is no published course reversal? Coming from the SW on the RNAV RWY 15 KONO, how do I align myself with the final approach course? There is only one IAF and no published course reversal. Is it up to me how I get established inbound?[RNAV 15] <Q> If the approach doesn't contain a publi...	If you just fly somewhere and ask tower for the approach you will get direct to PIYID.
Why does the B-52 have such a tiny rudder? The B-52 (aka Stratofortress, aka Grey Lady, aka BUFF) has a minuscule rudder for an aircraft of its size and wing-mounted engine placement: Compare to, for instance, the rudder on a 747: The B-52’s rudder is so small that it can’t be used to decrab the aircraft during a c...	More importantly the original designs had sufficiently larger control tabs but this lead to an elevators and a rudder that had a lower critical mach number than the wing (i.e. the empennage would stall first). The design was also too heavy for the tail structure to sustain.
ATC calling out regional airlines in traffic advisories: phonetic or "aircraft paint" airline used? When ATC points out traffic that is a regional airline (e.g. Compass, Envoy, SkyWest, etc.), do they use the phonetic callsign of the airline, or do they use the callsign of the airline that they are operating as (how th...	More often, however, ATC will just call the type of aircraft (737, A330) and its bearing and distance rather than say the airline it flies for. For carriers known to use multiple paint schemes, they just call the type unless they can see the paint themselves from the tower.
How do I keep a C172 straight on the centerline during landing/rollout? During rollout upon touching down, I'd often find myself veering off the runway centreline to the left. Every time I input rudder, I have this feeling that I am getting pulled out of the turn (while that is normal just like turning round a corner a...	To counter this, first, remember to get the final approach stabilized ie on centerline, on glidepath, and on airspeed as soon as possible after rolling out from the base to final turn. Remember, fly the airplane all the way through the landing, including the complete rollout. Very good advice to hold nose gear off whil...
Can we change light aircraft skin from aluminum to foam and fiberglass? Can we change the skin and wings of light aircraft from aluminum to foam and fiberglass composite in zenith ch 750 ? <Q> Yes. <S> No. <S> A little bit of yes, but overwhelmingly a NO. <S> Not because of any intrinsic properties of fiberglass, but...	It's possible to design and build an aircraft like the CH-750 with fiberglass instead of aluminum, but it's so far above the skill and qualifications of anyone who would ask the question on the web - as opposed to starting by modeling it in ANSYS - that the only realistic answer is "no".
Is there a practical carbon-free jet fuel? For example, when I want to use a small turbojet or low bypass turbofan as both the APU and bleed air supplier for blown flaps, ailerons, elevators, (like the ShinMaywa US-2 amphibious plane) and rudders, (and hot wing deicing) there's a lot of internal ducting, and a large ...	To answer the question as stated in the header, hydrogen powered aircraft have been tried with some success (they fly since about 1989).
Is it legal for pilots to transport or use marijuana? More and more states are legalizing the recreational use of marijuana. What does that mean for pilots? Is it legal for pilots to transport marijuana within states that have legalized it? Can pilots use marijuana recreationally if their state allows it? Are there ...	According to Federal laws, marijuana is illegal and your license (or medical) is not valid even if the state you are in allows it legally. So it may be legal to transport it, but you certainly can't be the one using it.
Was the Space Shuttle aerodynamically neutral while piggybacking, or did the combination act like a giant biplane? Trying to investigate this question, I see that 'Ask the Captain' says: The weight of the shuttle is calculated like any payload. The 747 produces enough lift to fly and to carry the weight of the shutt...	The shuttle was creating lift, but how that affected it aerodynamically is hard to say
Do all aircraft carry depleted uranium as counterweights? I was told that most aircraft had depleted uranium on board as counterweights. I have not seen one myself. Do all current modern aircraft have depleted uranium on board? <Q> From my research, it looks like about 0.1% of all aircraft carry depleted uranium counte...	So no, very few aircraft use depleted uranium counterweights.
What is this object in the cockpit of an ultralight? This is a tool (probably) in on an ultralight airplane. Initially I guessed that it is a tilting meter (to level between right and left), but seems it is not as it just a vertical tube filled up with something like liquid. So, what is that and how does it work? <Q> ...	It's indeed an airspeed indicator. The pitot inlet is at the bottom and the pitot air pushes a little red plastic disc up and down on a central rod, with a calibrated clearance between the edge of the disc and the walls of the tube.
What are some Anti-icing solutions for small planes without an on-board system? When flying during the winter, is there anything I can do to increase my margin of safety, such as anti-icing fluid? I've heard of people spraying their aircraft with propylene glycol, but am curious to know if this will do anything to pre...	Anti-icing fluids such as TKS are very effective, but the aircraft must be equipped with a system to properly disperse it to be certified for flight into known icing conditions.
Can a 777X legally be ferried with one or both wingtips folded? The 777X family (777-8/-9/-10) features wingtips that fold up on the ground to let the aircraft fit in tight spaces. These have to be extended and locked in place before a revenue flight can take place, but can a 777X legally be ferried with one or bot...	It'll depend on whether Boeing did any experimental flight testing to document the airplane's behavior with tips folded or removed.
Would a propeller extracting air from a cylinder with holes in it be an ideal lift apparatus for a VTOL aircraft? I am wondering if enough lift can be created for a VTOL aircraft using a propeller that is extracting air from a cylinder which is closed at one end and has holes in the top half of the cylinder. Please re...	A propeller can only reduce the air pressure in the cylinder by a small amount.
Why would a C150 tachometer bounce so much that the needle fell off? On a long flight in a C150E, the tachometer started bouncing a little bit and the severity of the bouncing gradually increased until it was extreme: The tachometer was spinning in loops and making a loud screeching sound. The counter continues to inc...	The most likely cause of this problem is a lack of lubrication in the drive shaft for the tachometer.
How is one's hypoxia resistance affected by the time of day? I am doing my PPL course in the Czech Republic and here they have the following question in tests: when during a day is the resistance of a human organism to hypoxia the best? There are 3 possible answers: 3 am 12 am 5 pm What is the correct answer and ...	The symptoms of hypoxia are more abundant at night, so I think you have your answer there.
What are some drawbacks to having a wingtip propeller on an aircraft? I was reading about aircraft concepts that involved wingtip propeller design and was wondering what the drawbacks of such a technology would be. I could not access the full paper but came across this: https://arc.aiaa.org/doi/pdf/10.2514/3.44076 ...	To me a showstopper disadvantage of wingtip propellers is that they are potentially disastrous in crosswind or landings, or landings with significant turbulence. You could damage a prop and suddenly have asymmetrical thrust at the worst possible time.
What is Density Altitude? I'm trying to get a deep understanding of the term: Density Altitude. So I have read the explanations in my instruction book, and online articles. One source explained it differently then the other which confused me. Wikipedia defines Density Altitude as: The density altitude is the alt...	Density altitude is a measure of density.
How do planes know what altitude they're cruising at? I know that when planes enter the aerodome containing the airfield of destination, the ATIS will tell them an altimeter setting so the system knows how to calculate their altitude above their field; what about in cruise? Do they listen to the ATIS of every sector wh...	Yes, smaller planes listen to ATIS/ASOS/AWOS or ATC while enroute below 18,000 ft (in the US) and adjust the altimeter setting in the Kollsman window accordingly.
Why does a sport certificate have no distance restriction while recreational does? A recreational pilot certificate only allows flights within 50 miles of home airport. A sport certificate has no distance limits even though it's easier to get - no medical certificate, less flying time and less instruction. What's the r...	Because a sport pilot certificate requires the applicant to undergo at least three hours of cross country flight training whereas a recreational pilot certificate does not have that requirement.
Why do airlines seem to go out of business suddenly? FlyBMI are currently in the news for failing and stranding passengers abroad. This is not the first time an airline has halted operations seemingly overnight and left passengers without a way to get home. Why is it that airlines stop operating so suddenly, compared...	Mainly because winding down airline business will turn it into a sudden and from there on increasing loss.
Why is carburetor heat unnecessary at full throttle? Questions like How does aircraft design affect carburetor ice? show how carburetor mount point affects the relative passive heating of the carburetor by the engine, but I've never learned why full power eliminates the need for carb heat. Looking at how Wikipedia ...	On a fuel injected airplane you only have the butterfly valve without fuel present, and the temperature drop from that alone isn't sufficient, and therefore you don't need carb heat on injected engines (just an alternate air source in case of impact ice on the air intake).
Can a VFR flight follow an IFR route? Can a VFR flight follow the same route of an approved IFR route (such as those found on Forefight Route Adviser) using waypoints and Victor airways? <Q> Yes. <S> In fact, before GPS came along, if you were flying somewhere and wanted to use your VOR to get from A to B, that's exa...	In the GPS era nobody uses VORs very much any more and you can fly direct almost all the time when VFR (I haven't used the VOR in my plane in eons; mostly I just use a tablet or my phone), but there is nothing to stop you from flying along an airway if you feel like it.
Does the ditching switch allow an A320 to float indefinitely? I watched a documentary yesterday about the Hudson River ditching of US Airways Flight 1549 . In the documentary, one of the investigators explained that the reason the water was entering so quickly was because the FO did not have time to hit the 'Ditching'...	The switch is there so slow down water ingress to allow more time for evacuation, not completely prevent it.
What prevents aircraft with a tailcone APU from using tail-mounted airbrakes? The BAe 146 and Fokker F-28 , which are virtually alone among jetliners in lacking thrust reversers, compensate by using large, tail-mounted airbrakes to help slow the aircraft during descent and landing: (Image by Adrian Pingstone at W...	Yes indeed, it is possible to combine an APU with air brakes at the rear of the fuselage.
Why would the Pakistan airspace closure cancel flights not headed to Pakistan itself? The India-Pakistan feud has heated up again, with Pakistan closing its airspace as a result. I know many international routes fly over Pakistan, and that the closure would cause issues, but this report surprised me: Thousands of ...	Also, if the diversion around Pakistani airspace would stretch the endurance of an aircraft beyond what fuel it can carry, it cannot fly the route.
Why don't American passenger airlines operate dedicated cargo flights any more? I was reading recently that Northwest Airlines was the last American passenger carrier to operate dedicated Cargo aircraft. Why do none of the large US airlines operate dedicated cargo flights anymore? This seems to be common among internat...	Unless an airline's cargo subsidiary is large enough to get the required economy of scale, along with decent market conditions, it's not worth the trouble and expense. Alaska Airlines, Hawaiian Airlines still have dedicated freighters.
How to calculate service ceiling and absolute ceiling in PA-44 Seminole? I am hard to understand to calculate service ceiling and absolute ceiling in PA-44 Seminole. Is there anyone know how to calculate it in the condition(T/O weight: 3599.24 L/D weight: 3354.44 PA:2329 Temp:20) <Q> You can use the given chart to defi...	service ceiling is the altitude where both engines running aircraft is able to climb at 300 ft/min at present gross weight and local OAT.
Does altitude influence the flight range of an engine driven aircraft? I'm reading a chapter about flight performance during the cruise phase and the influence of altitude. My book (Aerodynamica, prestatieleer en vliegtuigtechniek by Bas Vrijhof on page 155, written in Dutch) describes the following: Naarmate de h...	Jet powered aircraft have the best endurance at their optimum altitude.
Why don't flight attendants get tired when passengers can, despite sleeping? This Reddit thread refers to "stressors of flight" (many of these stressors are also present in automobiles) , sudden altitude adjustment, lower cabin humidity. , proximity to strangers . Yet flight attendants face these stressors too, but...	In other words: one possible reason why flight attends are not constantly tired by flying is because if they were constantly tired by flying, they wouldn't be flight attendants.
Is the A-10's cannon effective against tanks? Perhaps this isn't on-topic, but is the A-10 effective against tanks (tank armour) when using its cannon? For example, this page claims: Using the cannon, the A-10 is capable of disabling a main battle tank from a range of over 6,500 m. Is that true? If that were so...	Define effective Using the cannon, the A-10 is capable of disabling a main battle tank from a range of over 6,500 m. While modern battle tanks have quite sophisticated armor protection (for the crew), there are many vital components with less protection.
how are UAV systems (aircraft+ground facilities) fitted with landing aid system? For commercial aircraft, precise landing aid systems (ILS, GBAS) are required for autolanding, but these navigation systems are too expensive to be used for UAV operations. However, a lot of UAV OEMs have claimed and demoed landing the fix...	Smaller UAVs could land based solely on GPS without external help on airstrips built for bigger planes, because that 3m difference is good enough.
How many serious airline accidents have been caused by design faults alone? That is, in the chain of events that led to death or injuries in an airline accident , how often has a design fault been solely responsible? By a design fault I mean a problem such that even if the equipment: were maintained and operated t...	The Kegworth air disaster , when a fan blade on the uprated CFM56 engine of a Boeing 737-400 broke and the different sourcing of flight deck air caused the pilots to shut down the good engine.
Is it common for automated control systems to use non-redundant sensors? While reading an article about the Lion Air Crash with a Boing 737 Max 8 , I was very surprised by the following paragraph: In designing the 737 Max, Boeing decided to feed M.C.A.S. with data from only one of the two angle of attack sensors at...	Except in certain configurations, namely autoland, autoflight functions are usually fed with one set of sensors.
How does having a bigger engine placed slightly more forward and higher impact the plane in pitch? I'm asking about general aerodynamics for under-wing twin-jets – I'm not after information/speculation on the Max 8 crashes/systems, but I mention the crash below because of what I see as an unclear (to me at least) exp...	Moving engine forward creates more area ahead of the center of lift as viewed from directly underneath the aircraft, which affects pitch stability at higher angles of attack.
Why would a jet engine that runs at temps excess of 2000°C burn when it crashes? Airline engines are designed to work at very high temperatures. Yet, when a plane crashes they're burnt (see below). Is it something in their design? ( bostonherald.com ) <Q> How The Jet Engine Works : <S> Inside the typical commerci...	Most sections of the engine are not designed for that high of a temperature and may well oxidize or deform in the post crash fire.
Where are the grounded 737 Max planes being kept? With various countries grounding the 737 Max, where are they (their carriers) keeping the grounded planes? Are they simply being kept at Gates of various airports (which I doubt since gates are expensive and/or logistical reasons)? Are there "holding areas" at some air...	They're at whatever airport they were at (or next landed at) when they were grounded.
Are pilot YouTubers breaking any rules? Recently, I've been watching a few YouTubers (mostly FOs) who make great videos like this: Then I realized... They must spend a lot of time setting up cameras, playing with them, hitting record and stop etc. This could potentially distract them or make them miss something (a ...	Activities such as eating meals, engaging in nonessential conversations within the cockpit and nonessential communications between the cabin and cockpit crews , and reading publications not related to the proper conduct of the flight are not required for the safe operation of the aircraft. I remember reading or hearing...
Why is not every airplane equipped with 3 angle-of-attack sensors? For critical systems, redundancy is built into the system. It is common knowledge among designers/architects to have three different inputs so in case one is faulty, input from the remaining two can be used to find (and shut off possibly) the faulty one...	Double redundancy is used to detect a fault but cannot exclude it, so the system stops operating. Double and triple simultaneous faults can and do occur with common causes including environmental factors (AF 447), maintenance errors (XL 888), and birdstrikes (US 1549).
Why would a flight no longer considered airworthy be redirected like this? I ran across this tweet covering the saga of Smartwings 1201, a 737 MAX 8 that was apparently redirected from Prague to Ankara after the MAX was grounded by the EU. ( flightaware.com ) It seems like an odd decision to do this. The plane had ...	They were redirected to an airport that had a maintenance facility that the airline uses
Why do passenger jet manufacturers design their planes with stall prevention systems? I understand why passenger jets use software that overrides pilot inputs that might cause the jet to exceed the flight envelope. But why do passenger jet manufacturers design their planes with stall prevention systems? Shouldn't pro...	Well, stall is a limit to flight envelope, the one exceeding which is most dangerous, so stall prevention system is one of the systems that override pilot input if it would lead to exceeding the flight envelope.
Why don’t airliners use stabilizer movement to assist with large pitch control inputs? Most large airliners not only have elevators for pitch control, but also moveable horizontal stabilizers. The elevators are used for primary pitch control, with the stabilizers being used to trim the aircraft, and, for some airliner...	At low speeds sudden pitch changes would put the aircraft in danger of stalling, as airliners typically don't have the kind of thrust needed to sustain high pitch attitudes, or the type of wings that operate well at high angles of attack.
If all control surfaces were disabled, could a passenger plane be controlled by distribution of the passengers? Let's assume that a large military plane has its control surfaces disabled in combat. The engine(s) can still be controlled. There is a substantial number of ground forces being transported. In theory could ...	A practical application of moving passengers would be to help flare the aircraft just before landing.
Why can’t more older 737s be retrofitted with more newer winglets? Some background: there are four different types of winglet that have been used on various 737s over the years. The mini winglet is used to retrofit 737-200s (one of the two 737 Original variants, the other being the 737-100). It is basically a tiny...	Because of how aircraft certification is handled, it doesn't make sense to test a modification for a model that can't sell enough units to pay for itself.
Why is indicated airspeed rather than ground speed used during the takeoff roll? My instructor asked me this question during my lesson and I couldn't come up with any answers. He asked why do I need to look at the indicated airspeed rather than ground speed when in takeoff roll or as soon as we touchdown? It would be...	What counts is the amount of air that flows over the wing in order to takeoff, not the speed relative to the ground.
How are V speeds spoken? How are V speeds spoken? --Research for my novel. Is it the V and the number or letter notation or is there something more to it? The Wikipedia Page on V Speeds does not delve into the subject matter. I did search the search box, prior to submitting, but nothing has come up. Please don...	Vr is typically announced as just "rotate"
What is the maximum holding time? When arriving at a busy airport, airliners may be stacked in holding patterns, increasing flight time. I know airliners are required to carry extra fuel in case of rerouting (including a safety margin). Once in holding pattern, aircraft may be reordered (not as simple as a FIFO), th...	No, there is no limit.
Is there a general approach for designing a Trimmable Horizontal Stabilizer? What is the general design flow when designing a Trimmable Horizontal Stabilizer (THS) and the attached elevator? I assume you would dimension the max. positive/negative deflections of the THS to meet longitudinal trim requirements over all c...	Next, you pick the tailplane size and deflection range which covers all load cases and verify the result in the wind tunnel and flight test.
When is squawk 1000 assigned in USA? From Are squawk codes used with ADS-B? : Yes, squawk codes are still used and required with ADS-B. The post is 3 years old though. And from Wikipedia List of transponder codes : 1000: Used exclusively by ADS-B aircraft to inhibit Mode 3A transmit (USA) The way I understand...	I have not heard 1000 assigned in my flights around/thru the Boston (MA) Class B, down to the Cape area, or out to middle of NY state.
Are taller landing gear bad for aircraft, particulary large airliners? Buiding larger engines for larger aircraft as opposed to smaller but many engines has proved to result in more fuel efficiency.Having established one of the main drawbacks or impediments to building larger engines are ground clearance for engines in...	Taller landing gear do present challenges due to increases in leverage and greater amount of space, but this has already been dealt with in large delta designs such as the XB-70 and is certainly not insurmountable.
When to turn from crosswind to downwind to base in a circuit? I was told by my instructor that my circuit spacing is inconsistent. I do not know how to look at the runway and use it to judge when to turn downwind and base. As a result, my base leg is sometime high and sometime low. How do you determine when to turn at...	One way to help with judging the 45 degree aspect of a runway with a well defined threshold edge is to study the apparent angles of the runway edge closest to you and an imaginary line extending along the threshold's edge, relative to the horizon.
How long to clear the 'suck zone' of a turbofan after start is initiated? I recently found this (IMO funny) picture. All funny and all. But let's make this a real situation. Let's suppose I see my crush and his BF doing this, and I come with this 'genius' idea (alright, it's anything but a genius idea, but still) to s...	A start on a TF all the way to idle is about 20-40 seconds depending on the engine, and the fan itself won't do more than creep a bit until the core actually lights off which is 5-10 seconds, so they'll have lots of time to get down and get away as per @ymb1's diagram, once the wheeEEEEEEEEEEtickticktickticktickticktic...
Why aren’t there any lifting-canard airliners? A lifting-canard aircraft, such as the Long-EZ , is an aircraft with the main wing at the back end of the fuselage and a pair of small, highly-loaded canards attached to the forward fuselage; the canards fly at a higher angle of attack than the main wing, and, consequen...	You either need to have a less loaded canard (there goes your natural stability) or flaps on it, or some other aerodynamic kludge.
Can a civilian purchase a new (Not Retired) fighter jet? Let's take a jet like the F22 for example. Strip all the classified systems/weaponry out of it (civilian wouldn't need that), and just leave the basic aircraft itself. Could a civilian technically purchase this aircraft for personal recreational use/travel? Or ...	There may be basic aircraft systems that have restrictions. A pilot would need to get training on the aircraft which would be hard to find outside of the military.
Why do airplanes bank sharply to the right after air-to-air refueling? Whenever I see videos on YouTube they bank really sharply to the right after disconnecting from the tanker. Why wouldn't they do a more shallow 30-degree bank? See this video for reference: <Q> Fighter jets are very maneuverable, so they may make a...	Keeping the formation in such a way that the pilot can always escape to the right is probably done to ensure safety, as it lines up with the engrained training.
How to apply the TO/GA time and EGT limits? If there is a published 1) EGT limit and a 2) TO/GA time limit, which one should be applied when the EGT is well below the EGT limit and possibly even below the 'max continuous' EGT. Particularly with consideration of terrain avoidance procedures that require climbing to a hi...	The TO/GA time limit and the EGT limit are hard limits mandated by the approved flight manual.
What does rudder input control in normal law in an A320? I understand form documentation that in normal law, pedal input is not necessary to keep coordinated flight. It is merely said that using the pedals is not necessary. Later in the documentation it is said that the law for the yaw axis is either normal, alternat...	On all Airbus FBW aircraft, the rudder pedals normally control the sideslip angle, beta.
Why would a flight take a detour on clean weather? I was in a flight recently (march 22nd) from SBCF to SBGR (Brazil). It's usually a 1h10m flight, but mine took roughly 20 minutes more. I saw the flight path in FlightAware and there's an unexpected (to me) detour mid-flight: I looked for other instances of this sche...	If it's an international flight they may not be allowed to overfly the airspace.
Is it OK to decorate a log book cover? I'm a student pilot and am thinking about putting a tasteful decal on my log book, if for no other reason than to identify it as my own. Is that OK, or would that be frowned upon? Thanks. <Q> I don't belive there is any regulation against it. <S> Keep in mind you may need to ...	It all depends upon how your logbook will be used.
Are there more accidents in winter months, and if so, why? I was watching The Flight Channel videos and have noticed that the accidents seem to happen more often in winter months (for the Northern Hemisphere). Are there some statistics to back this claim? It seems logical: Winter months means icing on wings, slippery ...	Well its simple, *most GA planes dont have ani/deice equipment so winter flying in the northern parts of the country is out of the question for many GA pilots.
What are the advantages/disadvantages of in-fuselage engines (eg most fighter jets) vs wing/fuselage mounted engines? Most modern jet fighter designs incorporate their engine(s) within the fuselage, while most other medium/large aircraft mount them either under the wings or on the rear fuselage. What are the advantage...	To allow supersonic performance, low drag considerations such as the area rule are more easily met with in-fuselage engines. difficult installation (so more time spent on maintenance) lots of noise
How do conventional missiles fly? With the exception of cruise missiles, most missiles don't have any obvious lifting device. If you watch a missile being fired, prior to its rocket firing it does exactly what you'd expect: momentarily plummet toward the earth. And yet the moment it ignites, it stops falling completel...	Missile meant for longer-ranged engagement may employ a lofting profile during the boost phase, opting to use the rocket motor to gain altitude as well, in which case the thrust will directly offset some of the weight of the missile.

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