Questions tagged [airliner]
An airliner is a large, commercial aircraft operated by an airline for transporting people and/or cargo.
262
questions
70
votes
10
answers
87k
views
Why do jet engines get better fuel efficiency at high altitudes?
I'm told that this is true, but I can't imagine why. It seems like the fact that there is less air would make the engines less efficient... But that probably just shows how little I know about jet ...
- 23.6k
41
votes
11
answers
53k
views
Could an electric engine provide the same performance as jet engines on current aircraft?
I have looked at various questions on this SE site regarding this topic but I have not really found a satisfactory answer. Some comments here regarding torque and power in electric motors vs gasoline ...
- 521
30
votes
3
answers
15k
views
Why are propeller engines uncommon on airliners?
My experience in aviation is essentially zero, but looking at Wikipedia it seems like the Tu-95 Bear offers high subsonic speed and extreme range.
I assume that turboprop engines are more fuel ...
- 573
66
votes
3
answers
71k
views
What is the purpose of the sharp pods under airliner wings?
What are the pods with the sharp trailing edges underneath the wings of large airliners, as shown in the image below?
My best guess would be fuel tanks
- 1,948
46
votes
5
answers
10k
views
How do airliners get from the factory to the client if the aircraft does not have the required range?
Today I flew on an Embraer 190 of Kenya Airways. Checking in the tech specs this aircraft has a range of roughly 2900 km. Considering it is built in Brasil, I was wondering how do they deliver it to ...
- 9,754
46
votes
3
answers
66k
views
Are cargo holds pressurised these days?
This question is only regarding aircraft that seat more than about 100 people.
Are cargo holds pressurised these days, what is the situation?
Are only some pressurized, most, of every single one? ...
- 463
24
votes
3
answers
15k
views
What does it take to turn a 747 around 180 degrees?
Assume that a 747 is flying at cruising altitude and speed. If the pilot decided (for a presumably good reason), to turn the plane 180 degrees,
How quickly could the turn be completed?
How wide would ...
- 343
29
votes
6
answers
16k
views
For large jets, what is the primary means of slowing down after landing?
I understand that a large(r) commercial jet slows down after landing using the following methods:
Wheel brakes
Reverse thrust
Spoilers/flaps/airbrakes
What is the effectiveness of each compared to ...
- 7,333
59
votes
9
answers
47k
views
Why not mount airliner jet engines above the wings?
It seems that most airliners put the engines below the wings, i.e. the Boeing 7*7 series and the Airbus A3** series. This requires long (heavy) landing gear, and the engines are close to the ground ...
- 6,197
12
votes
2
answers
29k
views
How does the raked wingtip of the Boeing 787 work?
The wing tips are very different on these airplanes. The wingtip on a Boeing 787 is a sharp triangle, while the wingtip on a Boeing 737-300 is flat.
British Airways Boeing 787-8 G-ZBJC wingtip | by ...
- 9,147
19
votes
1
answer
12k
views
What are these antenna-like protrusions for on an airliner?
This is a JetBlue A320:
I've always wondered what these are for, but could never find the answer. I'm guessing a few of them are for receiving information from satellites.
- 9,147
104
votes
15
answers
82k
views
Why are planes generally painted white?
When planes come off the assembly line at the factory, they're green:
So why are most painted white? Surely a darker colour would hide dirt better?
Is there a reason planes are traditionally white?
...
- 16.4k
72
votes
6
answers
28k
views
Why are fuel tanks in the wings filled first, and why are they used last?
When fueling airliners, why is fuel filled first in the tanks in the wings and then the center tanks? And why do they use fuel from the center tanks first and then from the tanks in the wings?
From ...
- 7,407
28
votes
2
answers
15k
views
What is the typical temperature of an airliner's hull during flight?
Some high-speed military aircraft like the SR-71 had real heating problems, but airliners also travel almost at the speed of sound, use most of their fuel to make up for frictional losses, so I would ...
- 7,315
29
votes
2
answers
12k
views
How much of an improvement would a 1% weight decrease on an airplane be to the industry?
Say I thought of a very easy and inexpensive way to reduce the takeoff weight of a commercial airplane (body, fuel and passengers) by 1%. How much would this mean to the industry? Would it make much ...
- 1,377
27
votes
6
answers
19k
views
Can large airliners do aerobatics such as loops?
This subject has been partially covered before here Is it possible to do a barrel roll in a large aircraft like a B737? and here Is it safe to roll an airplane that isn't approved for it?
If a ...
- 774
36
votes
4
answers
10k
views
Would failure to put on an oxygen mask during loss of cabin pressure result in death?
I was trying to explain to someone why the cabin is pressurized (no one wants hypoxia) and that led to discussion about the emergency oxygen masks available on airliners.
If a person didn't put on ...
- 1,703
24
votes
6
answers
5k
views
Can passenger movement in an airliner make it stall?
This question shows a couple of air hostesses dancing during mid-flight and the co-pilot came out of the cabin to record it.
This made me wonder: Can flight crew or passengers moving around in ...
- 241
59
votes
3
answers
26k
views
What are these things hanging off the trailing edge of the wing?
What are these things hanging off the trailing edge of the wing?
I've seen them in almost all of the aircraft I've flown in, and can't remember if they're exclusively Boeing or Airbus.
- 764
29
votes
5
answers
13k
views
Why do we use pylons to mount the engines on jetliners?
This question focus on jet airliners.
The De Havilland Comet's engine were mounted inside the wing, the Concorde's engines were mounted underwing (as many jet engines) but without pylon. It seems jet ...
- 16.1k
33
votes
6
answers
10k
views
Why do we never see high-bypass turbofan engines sharing the same nacelle on large airliners and similar aircraft?
I'm talking about this sort of thing (this is the fictional airplane from Casino Royale), rather than two (or more) engines per wing in individual nacelles:
If we ignore the weird 'drop tanks' on the ...
- 441
8
votes
3
answers
21k
views
What is the difference between Assumed Temperature and Derate takeoff thrust?
Airlines like to avoid a full thrust takeoff as it increases the wear on the engine. There are two methods to achieve this: Assumed Temperature and Derate.
In the Assumed Temperature method, the ...
- 39.2k
39
votes
8
answers
10k
views
Why don't airlines load their passengers like freight?
Apparently, the time for boarding and deboarding an airplane is a large cost factor and something airlines try to minimize but have trouble controlling because the passengers do it themselves.
A ...
- 7,315
19
votes
3
answers
10k
views
Why is the Tu-144 the only commercial airplane with canard configuration?
I understand the delta wing was chosen because of the supersonic cruise (like the Concorde), and canards were added to reduce the approach/landing speed. But canards may be used without delta wing (e....
- 16.1k
9
votes
1
answer
7k
views
How is bleed air used to start a jet engine?
I know that most jet engines on commercial jets are started either with bleed air from an APU or bleed air from the other engine... But I'm not exactly sure how bleed air actually starts the engine? ...
- 23.6k
33
votes
6
answers
17k
views
Why do airliners pitch up during cruise?
In my experience as a passenger, when the plane stands at the airport and you enter it, the aisle is pretty much horizontal. (Obviously, I've never flown on a DC-3). After takeoff we pitch sharply ...
16
votes
2
answers
11k
views
What exactly are those openings in the bellies of many jetliners?
I have circled the areas (in yellow) under the belly of the 737.
What exactly are those?
(airliners.net)
- 1,273
6
votes
2
answers
18k
views
How much fuel is used for the different phases of the flight of a typical airliner?
An Airliner flies from LA to JFK in 5 hours. In the first 30 minutes the plane climbs to about 30,000ft. For the next 4 hours the plane flies at about 30,000ft. For the next 30 minutes the plane ...
- 69
80
votes
8
answers
19k
views
Why do aircraft models end their life as freighters?
There seems to be a tendency that aircraft models are more long-lived for cargo than for passenger service.
For example, both the A300 and MD-11 are all but extinct in scheduled passenger service, ...
13
votes
3
answers
4k
views
Why don't airliners carry radar jamming technology or missile counter measures?
Why is it that commercial passenger aircraft that fly through dangerous areas don't carry some sort of electronic counter measure to defend themselves from missiles? Between terrorism and the various ...
- 23.6k
36
votes
12
answers
16k
views
Can a passenger jet be towed to safety if it breaks down in midair?
A car can be towed by a tow truck to the repair shop when it breaks down on the highway. Is it possible for a passenger plane to be towed by an emergency tow plane along the air corridor to the next ...
- 1,633
28
votes
3
answers
29k
views
Where does my pee go when I flush at 35,000 ft?
One thing I guess a lot of people wonder is: what happens you flush the toilet in an aeroplane?
Does it fall out the belly of the plane and disintegrate? :)
A kiwi woman complains that "aeroplanes ...
- 16.4k
9
votes
2
answers
3k
views
How much air is recirculated (vs. bleed air injected) in modern airliners cabin?
Air in the cabin of airliners is a mix between:
new air (engine bleed air or ram air in some aircraft) and
recycled air pumped out of the cabin, filtered and re-injected.
How much air is ...
- 67.7k
40
votes
6
answers
31k
views
What's the point in escorting a threatened flight with two fighter jets?
Two days ago I read in the news:
Two U.S. fighter jets escorted a Canada-to-Panama flight back to
Toronto after a passenger allegedly threatened the plane Friday
morning. The nature of the ...
- 503
34
votes
7
answers
8k
views
Why are jet aircraft never designed with a slower cruise speed?
All jet airliners have a cruise speed between Mach 0.82 and Mach 0.85.
At those speeds the aircraft are flying at their maximum subsonic speed. Any greater cruise speed would only be ...
- 1,142
33
votes
1
answer
27k
views
Why is there a hole in one of the layer of an airplane's windows?
On a commercial airliner, there is a hole in one of the layer of the passenger windows.
See here:
and here:
Or in more detail:
Can you explain the physical reasons for this design choice?
- 542
33
votes
6
answers
88k
views
If a typical passenger plane had total failure of all engines mid-flight, is it possible for passengers to survive?
I have pretty bad flying phobia and often wonder what would happen if all the engines on the craft went out at the same time. I initially had the anxiety-ridden thought that the hundreds of thousands ...
27
votes
4
answers
42k
views
What is the typical touchdown vertical speed of a large airliner?
What is the vertical speed (range) of a Boeing 787 (or any other large commercial aircraft) that should be achieved just before and during touchdown? I'm not interested in the vertical speed during ...
- 4,622
23
votes
5
answers
7k
views
Is spin recovery possible in an airliner?
During initial flight training a lot of emphasis is placed on stalls and spins and how to recover from them, but is it possible to recover from a fully developed spin in an airliner? Do these large ...
- 7,333
13
votes
1
answer
2k
views
What are the design parameters for airliner safety?
Airliners designed to carry multiple airfare paying passengers are regulated by CFR 14 Part 25, and by EASA CS-25. The design regulations are such that the probability of a catastrophic failure with ...
- 57.8k
9
votes
1
answer
1k
views
Are there any fly-by-wire airliners with negative or near-neutral pitch stability?
Are any modern commercial airliners with fly-by-wire flight control systems designed with negative or near-neutral pitch stability so that they can take advantage of the capability of such systems to ...
- 4,418
25
votes
4
answers
5k
views
Why are heavy flaps better than just a bigger wing?
Flaps increase lift during landing and T/O. But when retracted, they do nothing. The space needed to stow the common fowler flaps can't be used for anything else - fuel or structure. Extended flaps ...
- 3,084
17
votes
1
answer
2k
views
What happens if a passenger dies mid-flight?
Last month (December 2014), there were news that a passenger passed away during a flight. As mentioned in this answer, it appears that it is not a very uncommon scenario.
In an unfortunate incident ...
- 29.1k
8
votes
3
answers
2k
views
Why are airliner cockpits not shielded from lasers?
With the recent increase in laser incidents reported by pilots, why don't airliner manufacturers shield airliner cockpit glass from lasers?
The Abrams tank is shielded, protecting the crew from ...
- 5,340
30
votes
6
answers
5k
views
Why isn't the wing span of a certain airliner longer with the longer fuselage versions?
The Boeing 737 next generation models (700,800,900ER) all have the same wingspan at 117ft 5 in. Why doesn't the wingspan increase with bigger and longer models? With the 737-900 wouldn't you need a ...
- 9,147
29
votes
10
answers
47k
views
Can a plane fly without the vertical stabilizer?
What would happen if a plane (for the sake of the question let's say that the plane is an Airbus A380) lost its vertical stabilizer?
https://commons.wikimedia.org/wiki/File:...
- 6,974
35
votes
3
answers
22k
views
Why don't airliners use in-air refueling systems?
Right now if an airliner wants to fly a really long distance (eg., a Boeing 787 flying from Seattle to Tokyo), it has to load itself down with lots and lots of fuel, which in turn weighs thousands and ...
- 23.6k
25
votes
6
answers
6k
views
What are the factors behind increasing aircraft window sizes?
Modern airliners like the Airbus A380 and Boeing 787 have bigger windows than older designs, like the Boeing 737 and Airbus A320.
What factors have led to this change of window size, opposite to the ...
- 11.4k
20
votes
2
answers
9k
views
What are these lines on the nose of a Boeing 737?
What are these lines on the radome?
You can also see them here:
What are they and what is their function?
Source: AviaFilms
- 11.2k
18
votes
5
answers
2k
views
Are there non-economic barriers to a 1000 passenger aircraft?
I know the number 1000 is just an arbitrary number that happens to have some zeros in it, but is there any non-economic obstacle to making a 1000 passenger aircraft?
Also, assume normal-ish space-per-...
