What would happen if you opened a plane's emergency door mid-flight


#1

Originally published at: http://boingboing.net/2017/07/17/what-would-happen-if-you-opene.html


#2

Man, getting sucked out of an airplane would be a shitty way to go…


#3

Weeeee!

even two pounds per square inch is more than any human being push

Isn’t it weird how humans are so often “beings”, but nobody else is? Have you ever heard of cat beings? Turtle beings? Lemur beings?


#4

#5

The vast majority of sky divers jump from altitudes that don’t require pressurization or supplemental oxygen. 12,000ft ISTR. Planes are designed to prevent the doors from opening at altitude to prevent anybody from trying to imitate DB Cooper. Of course there is usually a crash axe in the galley that is DESIGNED to be able to cut through the side of an airplane
edited to add: Not surprisingly, the crash axe in the galley has mostly been replaced with w pry-bar these days…


#6

Some bad science going on in this article:

The reason skydivers can jump from open doors is because those planes are depressurized

Oh, and because the skydivers are flying at 3,000 feet above the ground, not 30,000.


#7

Garbonzo beings.


#8

I hear that United is working on a exit door door that will open in mid flight to suck out ‘certain’ passengers.


#9

HALO jumpers don’t count as skydivers?


#10

Ecco homo, qui est faba.


#11

Wait, so airplane doors open inwards, not outwards? I thought they opened outwards, but honestly can’t picture it right now.


#12

The emergency exits open inwards. They’re basically a removable hatch that you pull in. The actual boarding doors have a much more complicated locking mechanism. They do open outward, but to do that, they need to first move inward.

If you think about it, it makes a lot of sense- if it opened outward, the locking mechanism would have to hold up against the pressure differential, making it much more complicated, heavy, and expensive. A failure of the locking mechanism would mean the door blows out, and you get an explosive decompression. A locking mechanism that needs to be pulled inward will fail-safe: pressure will hold the door shut.


#13

Plane doors were designed like that all along. DB Cooper had nothing to do with that engineering decision. He went out a ramp at the tail, which had to be hinged so it could be lowered, and it didn’t open inward. He IS responsible for the fact that there are no more such ramps on passenger planes, and that boarding and exiting are now such horror shows, since it’s no longer possible to board at both ends.


#14

Holy frijole…


#15

Not sure Cooper is responsible for ramps themselves being phased out, but he certainly inspired a defeat mechanism preventing the lowering of the ramp in-flight:


#16

“I call them man-animals.”


#17

Baaaah… Why not go tell it to OUR FRIENDLY BARTENDER? XD


#18

The doors of most jetliners actually open outward. (the emergency exits are another mater) Most large jetliners actually still have doors at the front and rear of the cabin, but the jetways that connect to the terminal only connect to the front, because creating a jetway that went OVER the wing and was idiot-proofed to never collide with the wing would be difficult.


#19

The main entry/exit doors of an airliner, although they do swing out, when in the closed position are positioned firmly enough against the airframe so the effectively they’ve got the pressure differential pushing them shut.

If you are working a hydraulic jack to pry open the door, you’ll probably reach a point where you’ve got just enough of the door open where it will depressurize in a slow, controlled manner – like letting air out of a balloon. It will probably be loud and the cabin will fog up instantly, but I’m guessing it wouldn’t do damage to the airframe.

Explosive decompressions typically happen along metal fatigue points in the aluminum skin of the airframe and are more akin to poking a balloon with a pin. And metal fatigue is an inevitable consequence of cycling – that is when a plane climbs to cruise altitude and back down again. After some number of cycles, a plane is required to be stripped of its interior and inspected inch by inch for fatigue cracks.

On a side note, airliners are continually exchanging air with the outside environment. A valve usually located towards the back of the cabin is carefully letting out air to maintain the desired cabin altitude pressure (8000-9000’ typically), and high pressure bleed air from the engines’ compressor is fed into the air cycle machine(s) (ACMs or “A/C packs”) which through various stages cool and prepare the air for the cabin.

When the air outlet valve goes screwy, terrible things happen (google “ghost plane”).


#20

Well, the most popular airliner, the B737, has a plug-style door that opens inward first then swings outward and cannot be opened when there is a pressure differential. Several others in the Boeing line are this way, the 747 and 757 namely. The 777 and 787 both open outward directly along with the Airbus airliners (as far as I can tell). The 767 is an oddball as it is still plug-style, but it slides upwards and is entirely in the aircraft.

I’m going to guess that the locking mechanism can’t be unlocked by a human during flight in any of the purely outward swinging doors, as there’s going to be a lot of locking pins and the door will be pushed outwards. The lock would likely require superhuman strength to actuate while there’s a pressure difference.