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An airliner is a large, commercial aircraft operated by an airline for transporting people and/or cargo.

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How much fuel does an airliner consume at various stages of operation? [duplicate]

I used to think that almost all of an airliner's fuel consumption was during actual flight; but it seems that even while on the tarmac or at a gate it consumes a non-negligible amount. So, in general ...
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When were the last subsonic turbojet-powered airliners retired from commercial passenger service?

The very first jetliners (Comet, Tu-104, Caravelle I-VI, 707-120/-220/-320, DC-8 series 10-30, original 720, CV-880) all used turbojet engines, turbofans not being available until later; when ...
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Why then don't aircraft fly even higher, for even greater efficiency? [duplicate]

After reading various superb QA on here I now see that (basically) aircraft are more efficient per passenger-mile, at higher altitudes. Why don't we go even higher, than current typical airliner ...
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Lift to drag ratio of airliners

I don't know if this is the right place to ask, but I am looking for lift-to-drag ratios (L/D) of different airliners. I have found a paper [1] which has some estimates of L/D for some jetliners, but ...
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4answers
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How did the 9/11 hijackers find their way to NYC?

It is quite well known that the airplane hijackers on 9/11 were not professional pilots. So, my question is how some people who didn't have any experience of navigating the airplanes could find their ...
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Why aren't there any widebody propliners for the high-density short-haul markets?

Jetliners come in both narrowbody (one aisle) and widebody (two or more aisles) versions, but all propliners, to the best of my knowledge, are narrowbody aircraft. Now, granted, one of the big ...
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Can audible warnings be heard from the cabin?

When I fly in the front row on an all-economy A320, I can very clearly hear the autopilot disconnect sound shortly before landing. Can passengers in the cabin also hear other warnings like EGPWS (...
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1answer
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How and how often are the oxygen masks in the cabin checked?

Looking at this old answer I can see that oxygen masks check is mandatory for the flight deck. What about passenger masks? Is this check done daily on airliners? How is this check conducted and what ...
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3answers
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Why does load shedding still occur in jetliners (e.g., 787) when there is so much power available?

I had a few questions about how electrical generator works on an aircraft, the 787 to be specific although I know it is similar for all aircraft. So the 787 engines have 2 VFSG each which are rated ...
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2answers
99 views

What are the technical details of how airline seats are installed on an airliner? [closed]

What are the technical details of how airline seats are installed on an airliner? The step by step. Not made how they are installed.
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1answer
175 views

If an airline purchases an aircraft, do they have to/feel compelled to change the livery?

If an airline purchases a used commercial aircraft, which would be painted in the livery of its previous owner, would the new airline ever be required (by law) to re-paint the aircraft in their own ...
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What is the 'fuel cost' of a pneumatic braking system vs. a hydraulic one, in terms of weight?

A pneumatic braking system has indisputable advantages over a hydraulic braking system for large and heavy aircraft in terms of braking force and secondary perhaps in terms of weight (pipes and ...
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319 views

How much fuel does an airliner consume during passenger boarding?

As I understand, sometimes APU is running during the passenger boarding. How much fuel do the APU consume during this process? Of course, it must depend on the total boarding time, so I think it ...
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2answers
2k views

What are the most challenging taxi manoeuvres that a typical commercial airline pilot must execute?

I am currently involved in a University level modelling excercise which looks to investigate the handling qualities of a novel nose wheel steering system. As part of this study, I am interested in ...
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2answers
424 views

Why two passenger airplanes travel side by side?

Recently (2018-08-19 17:40 UTC) two planes flew above my city (Poznań, Poland). They were heading in the same direction, kept really close distance (side by side) - both flights to Riga: https://www....
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5answers
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Why do airliners have to park so accurately?

I was watching some airport documentary and I noticed that the planes always had to park precisely. I honestly didn't think so much of it before, but in the documentary, an aircraft parked badly ...
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4answers
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Has any passenger airliner ever offered forward-facing windows?

The empty, dolphin-like, forehead of the A380 seems like it would be an amazing place for the first and/or business class bar, especially if it had forward-facing windows. I realize in the A380's ...
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1answer
406 views

Why did my flight descend for landing then suddenly climb steeply and turn sharply?

I was flying on a Vueling flight (VLG6251) from Rome, Italy to Orly, France on the 31st of December 2017. During landing, my plane went to a really low altitude as if it was about to land but there ...
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1answer
353 views

If everybody jumps in an airliner, would the pilots notice? [duplicate]

I often have this thought when stretching my legs on a long haul flight: jump up and down in the cabin and see whether the pilots complain. Alone, it is unlikely my weight would have any noticeable ...
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2answers
281 views

What would happen if pilots were locked out of the flight deck?

Imagine in a hypothetical situation that a commercial airliner was left on autopilot at some cruising altitude. Next imagine that all pilots left the flight deck and the door slammed shut behind them (...
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1answer
334 views

Can you escape an aircraft through the lavatory?

In his book "Catch me if you Can", Frank Abagnale claims he evaded arrest by removing a panel in the lavatory of a VC10, climbing through it and hence escaping out of the (taxiing) aircraft through a ...
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5answers
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Why, until recently, were smooth nose sections not popular?

Why, until recently, were smooth nose sections not popular? By smooth I mean without a break between the nose and windshield. (The question focuses on airliners.) Seeing the Starliner (left) and DC-7 ...
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Are there any airliner crashes that can be definitively attributed to Mach tuck?

Mach tuck (the tendency of aircraft to develop an increasingly nose-down pitching moment at speeds above its critical mach number) caused a number of crashes of high-speed fighter aircraft before the ...
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How significant is the lift induced drag contribution to total drag of aircraft at cruise speed?

How significant is the lift induced drag contribution to total drag of aircraft at cruise speed? From what I've learned so far it seems to be around 10 to 15 percent of total drag. I suspect the ratio ...
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290 views

What are the drawbacks for manufacturing a large airliner capable of water landing?

Emergencies are rare but still occur. Apart from weight and extra fuel costs, What are the drawbacks for manufacturing a large airliner capable of water landing in case of an emergency? Assuming the ...
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Single Engine operation on Twin Engine aircraft [duplicate]

I recently came across ETOPS and I wanted to know: How does a twin-engined aircraft balance out the lack of thrust on one side in the event that one of the engines is non operational? Any ...
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3answers
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Why is the lower deck of the Airbus A380 curved like a single deck airplane?

I recently traveled on the lower deck of an A380 and the section where the side walls of the fuselage and its roof top meet is curved just like any single deck airplane. Credits: Wikimedia Commons ...
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1answer
199 views

Are radio channels used by airliners half-duplex channels?

Can a pilot transmit and receive information at the same time? Or can he either transmit or receive but not at the same time? I thought communication channels were half-duplex because this reduced ...
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1answer
866 views

Can anyone tell what kind or even which airplane this is?

As stated in this post on the Dutch Police website (Google Translate English version) this morning (12th june 2018), they are looking for all available information concerning the image below. All help ...
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2answers
218 views

Why is it necessary for pilots to have trim controls on fly-by-wire aircraft?

On Airbus family airliners why is it necessary for the pilots to have the facility to trim when there is no aerodynamic feedback through the flight controls?
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2answers
2k views

What is the horizontal stabilizer failure procedure?

During the final flight of Alaska Airlines Flight 261: The CVR transcript reveals the pilots' continuous attempts for the duration of the dive to regain control of the aircraft. At one point, ...
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Why is there still a preference for turboprop airliners over the new regional jets? [duplicate]

In the 1950s and in the early 1960s, jets were mostly available as fighter/military or big, long haul aircraft. Regional aviation was based primarily on piston aircraft that could operate in smaller ...
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Were my airplane's wheels under-inflated?

I recently took a flight on a (Lufthansa) Bombardier CRJ900 aircraft. As I was about to embark, my eyes caught this image: And the aircraft wasn't even loaded with the passengers yet. If I saw this ...
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1answer
271 views

Could Mach 1.4 be a better design point for SST?

There's been a number of recent proposals for design work on low-supersonic bizjets that would cruise at Mach 1.1-1.6, the common theme being avoiding a sonic boom. I'm wondering if this range of ...
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Has there ever been an uncommanded lowering of landing gear?

Has there ever been an uncommanded lowering of the landing gear on a large commercial jet? I could not find any instance of it in a preliminary google search. Could a simple short-circuit cause such a ...
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3answers
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Why aren't Russian jet airliners popular even in Russia?

Russia has the proven capability to build large jet airliners. Ilyushin Il-96 Tupolev Tu-204 But, if we take a look at the major airlines in Russia, they don't appear to have Russian ...
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251 views

What happens to Ryanair aircraft after they leave the airline?

According to the fleet renovation and the short age of all their aircraft (6.5 years), what happens to Ryanair's aircraft after their time in the company? Are there other companies willing to accept ...
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3answers
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Why didn't early jetliners use turbofans?

For subsonic operation, high-bypass turbofans seem to have essentially only advantages for efficiency, noise and takeoff thrust, at least until they reach the size where ground clearance or LP/fan ...
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4answers
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Why would the Speedbrake be required for such a long time on approach? [duplicate]

As far as I was aware, the Speedbrake is designed to slow the aircraft down. On landing, I do understand why they are required. Once the aircraft has hit the tarmac, they are deployed to 1) slow the ...
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Where can I find power and heat specifications for EFIS and IFE systems?

I am working on an MSc. thesis project about the electrification of aircraft. Since the rule of thumb is to design the generators for the worst case scenario, I would like to include as much ...
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3answers
4k views

When does an airliner switch from using the tiller to the rudder?

When does an airliner switch from using the tiller to steer to the rudder on takeoff? Same for landing- when does the pilot switch from using the rudder to the tiller? What is this process? Once a ...
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249 views

Why should pilots keep the engines running so they are hot or warm immediately after landing?

Understandably, airliner pilots - particularly those operating in extremely cold climates and airports - should preheat the engine at idle for 3 minutes or more so they do not apply full thrust and ...
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1answer
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How much does weight really affect the operation cost?

Hi given an information from a reliable new source article (https://www.nytimes.com/2008/06/11/business/worldbusiness/11iht-air.1.13628276.html), it was mentioned that "Every 25 pounds we remove, we ...
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260 views

Where can I find a cross sectional area plot for the A320 or other modern airliners?

I'm studying to become a pilot and stumbled upon the Raptor Aircraft a while ago. In one of our subjects we briefly discussed the concept of the area rule but did not get into much detail since our ...
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371 views

Why isn't there a single start button for all systems on aircraft?

Why is it that airliners and aircraft do not have a single start button for all systems? On TV etc., I noticed that pilots pressing buttons above and below forward and sideways, mostly above though, ...
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How common are missile defense systems on civil airplanes?

I've just stumbled upon Why don't El Al 747's stay at the gates at JFK? in the hot topics. I kind of get why El Al decided to put missile defense systems in their planes but I was wondering: ...
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What should be the minimum time spent in cruise (for e.g. a B737)?

Having a short sector to fly, it would not be convenient to climb all the way up to the best cruise altitude, since the time in climb would burn more fuel than that necessary for a flight at lower ...
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698 views

Why are parking brakes not used for parking jetliners?

From the question 'Do I Set the Parking Brake On the Ramp?' it is concluded that you do not set the parking brake when parking the aircraft. The question concerns small aircraft which can be parked ...
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Is it illegal to partially block the aisle on a passenger airliner?

After reading all the commotion about the dog that died after its carrier was placed in the overhead bin I wondered- is it against any FAA regulations to allow a flight to take off with a partially ...
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1answer
159 views

What is the purpose of long endurance test flights?

Well known is the last long endurance test flight by a Boeing B787-8, which drew its shape in the air for 18 hours while on a long endurance test flight: https://www.wired.com/story/boeing-787-8-...