Skip to main content
107 votes
Accepted

How did the 9/11 hijackers find their way to New York City?

Several of the hijackers, including Mohamed Atta, held at least private pilot certificates and had undergone ATP level jet training in DC9 and 737 full motion simulators in December of 2000. Atta ...
Romeo_4808N's user avatar
  • 73.9k
96 votes
Accepted

Why do aircraft models end their life as freighters?

Passenger operations are overwhelmingly scheduled whereas cargo is on demand and thus less easy to plan. The upside: A cargo plane crew will fly quite diverse routes. The downside: Capacity ...
Peter Kämpf's user avatar
95 votes
Accepted

Why is the lower deck of the Airbus A380 curved like a single deck airplane?

The cabin interior is curved to accommodate, among other things, the brackets holding the upper deck floor beams. These brackets are a structural feature that transfers the weight of the upper deck ...
Therac's user avatar
  • 27.4k
82 votes
Accepted

Why do airliners have to park so accurately?

This is to ensure that there is space for all equipment around the aircraft. It's not critical to the centimeter, but if it's off by a meter or more there may be problems. For example, the tail may ...
Anilv's user avatar
  • 4,566
76 votes
Accepted

How hazardous is it if an engine cowl falls off?

I work in aero engine safety but not for the company that manufactured the engine in the event you mention. Parts falling off engines is Not Good. We worry about them hitting people below the ...
moink's user avatar
  • 835
75 votes
Accepted

Can a human get sucked into a jet engine?

Yes. Human beings can get sucked into jet engines if they are close enough- this has happened multiple times in a number of aircraft ranging from A319 to A6E intruder. However, it happens only in ...
aeroalias's user avatar
  • 100k
73 votes
Accepted

Has any passenger airliner ever offered forward-facing windows?

We could start with the Tupolev ANT-20 with its rather daring forward-facing passenger gallery. [edit - the prime seat right at the front in the gallery was for the navigator and his equipment.] ...
Party Ark's user avatar
  • 13.2k
67 votes
Accepted

What prevents a commercial jet from electronically "resetting" the way a computer sometimes does?

I'm a programmer and private pilot, so maybe I can help dispel some of those fears. The computers that run a commercial airplane are conceptually much simpler than the one that runs your phone. This ...
HiddenWindshield's user avatar
61 votes
Accepted

Has any airliner ever collided with a glider?

Yes. (I found this by Aaron Holmes's hint that he searched only English sources.) On 1999 Feb 12 at 3:40 pm, a Grob G103 sailplane F-CGXB (possibly "in wave flight") collided with an Airbus ...
Camille Goudeseune's user avatar
58 votes

How did the 9/11 hijackers find their way to New York City?

All of the hijacked flights were going in different directions and had to be piloted to a different destination. The hijacker pilots had different degrees of success in doing this. The flight paths ...
Tyler Durden's user avatar
  • 13.3k
53 votes

Can a human get sucked into a jet engine?

what is the minimum or maximum weight that these engines can suck? Quite a lot, considering they can ingest ramp equipment... This is a JAL 747 ingesting a baggage container. Delta L-1011 doing the ...
Moo's user avatar
  • 1,569
52 votes
Accepted

Can airliners be considered as GA?

GA refers to why you fly your plane, not what kind of plane it is. For example, John Travolta has (had?) his own personal Boeing 707, which is the first generation of jet airliner from Boeing. When he ...
Greg Hewgill's user avatar
  • 9,152
51 votes
Accepted

Can commercial airliners fly over central Antarctica during winter?

Surface air temperatures aren't really going to be relevant for an airliner. The temperature of the troposphere doesn't vary that much. In fact, the troposphere is warmer at the poles (from Wikipedia ...
Greg Hewgill's user avatar
  • 9,152
48 votes

Why are fuel tanks in the wings filled first, and why are they used last?

Having all the payload of a plane concentrated at the fuselage creates a large bending load on the wings in order to support that weight. Storing fuel in the wings allows some of that weight to be ...
fooot's user avatar
  • 73.4k
48 votes

Why is waste water from lavatory sinks dumped outside in mid-flight?

“Grey” water from the lavatory and galley sinks is dumped overboard through electrically heated drain masts. It is much cheaper and simpler to drain it overboard rather than store it. Dumping it also ...
Mike Sowsun's user avatar
  • 37.8k
47 votes

Why do airliners have to park so accurately?

I worked for 3 years as a ramp agent and there are two reasons: Jet bridges and safety. Jet bridges have plenty of leeway, but not a lot. This gets worse in winter because those things hardly move ...
Jonathan Kuhl's user avatar
47 votes

Why then don't aircraft fly even higher, for even greater efficiency?

Some do (or have in the past) but very high altitudes present their own issues. Historically the Concorde cruised anywhere from FL550 to FL600 and was actually allowed to climb and descend at its ...
Dave's user avatar
  • 101k
47 votes

Is 'bouncing' an airliner on landing in high winds a deliberate technique, or something always unexpected?

Bouncing a landing is neither intentional nor desirable. There are several reasons why a student pilot might bounce, but for a professional pilot, it's most likely related to wind gusts, which are a ...
StephenS's user avatar
  • 27.7k
45 votes
Accepted

Is gravity less on an airliner at cruise altitude?

There is less gravitational force, but by how much? An insignificant amount. The gravitational force of attraction between two objects is given by, $\displaystyle F_{\mathrm g} = \frac{G m_{1} m_{2}}{...
aeroalias's user avatar
  • 100k
45 votes
Accepted

Is there any emergency situation in which jet engines would not be shut down before passenger evacuation of a transport aircraft?

It is possible for the engine to not respond to shutdown sequence, so you'd have to get the passengers off before dealing with the rogue engine. In the Qantas Flight 32 one engine had an un-...
Notts90's user avatar
  • 3,569
45 votes

How much of an improvement would a 1% weight decrease on an airplane be to the industry?

There is an easy way to get an idea of what magnitude the savings are: The Breguet equation can answer this. You first calculate a reference aircraft and then start all over with one that weighs 1% ...
Peter Kämpf's user avatar
45 votes

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

I flew for two 747 carriers that never bought new aircraft, and thus this answer applies to 747-100/200 aircraft as originally manufactured for a number of different airlines. The tiller is active ...
Terry's user avatar
  • 39.2k
44 votes

Could an airliner exceed Mach 1 in a zero-G power dive and safely recover?

There is actually some data (albeit limited) on this scenario: On August 21st 1961 this test was performed in a DC-8. When this test was performed they were supersonic for about 16 seconds which took ...
Dave's user avatar
  • 101k
43 votes
Accepted

Could an electric engine provide the same performance as jet engines on current aircraft?

Not yet. To look at a medium-range aircraft, let's base the engine on the CFM56 or the IAE V2500. Those engines produce between 100 and 150 kN static thrust. In cruise, their thrust is considerably ...
Peter Kämpf's user avatar
43 votes

Why are heavy flaps better than just a bigger wing?

When flaps are retracted they do nothing, which is the whole point. The byproduct of lift is drag, a larger wing will create more lift, but more drag as well. More drag equals a slower cruising speed, ...
GdD's user avatar
  • 54k
43 votes

Can airliners land with auto pilot in gusty wind conditions?

To the first part of your question, the airplane is not moving BECAUSE his yoke movements are "strong and fast". Experienced pilots can feel a gust and respond with a control input to ...
Michael Hall's user avatar
  • 26.4k

Only top scored, non community-wiki answers of a minimum length are eligible