Possible to open exit door in flight?

I was reading this story and seemed to remember reading that due to the cabin pressure you can't open an exit door in flight. Is that true?

True. From Patrick Smith's Ask The Pilot:

 

At a typical cruising altitude, up to eight pounds of pressure are pushing against every square inch of interior fuselage. That’s over 1,100 pounds against each square foot of door. Even at low altitudes, where cabin pressure levels are much less, a meager 2 p.s.i. differential is still more than anyone can displace — even after six cups of coffee and the aggravation that comes with sitting behind a shrieking baby. The doors are further held secure by a series of electrical and/or mechanical latches.

 

I recommend to read the whole article, because it's pretty funny :D

http://www.askthepilot.com/questionanswers/exits/

If you use your strongest muscle it opens easily. No prob at all.

Now, correct me if I'm wrong, but it seems to me that, given the above quote, there is more pressure inside the cabin than out. Ok, makes sense. Now, to my thinking, what little I still do, since the exit doors open outward, doesn't the higher pressure tend to push the doors open? The overwing emergency exits, ok, fine, they remove inward, so the pressure holds them in place. I can see that. But the main exit/entrance doors open outward. If you can get the latches open, the door ought to be PUSHED by the higher pressure.

I can dig the various mechanical interlocks, that may be engaged, preventing the door from opening. Makes sense. Not to mention the pressure inside pushing the door, pretty hard, against the latches, tending to hold them in place, preventing opening them. Makes sense. Push hard against a door, hard to open the latch. Makes sense to me.

But if you have high pressure inside pushing, or, if you prefer, low pressure outside pulling (everything is relative, as Einstein once said), then the main exit/entrance doors should be pretty easy to open, once the latches are disengaged.

Consider this: What happens when the cabins structural integrity gets broken. Think of the Aloha Airlines 737. Small structural failure, BAM, large section of the cabin roof removes OUTward. Assisted by the pressure differential. Wouldn't the doors that open outward do the same?

Just makes sense to me. Higher pressure, door being PUSHED by such, door pops open easily.

All this is presuming the doors in question open outwards. If they open INwards, yes, virtually impossible to open. But for the same reason, and logic, if they open outward, if you can defeat any interlocks involved, and the latches, they pop open easily.

 

This is something that's bothered me. Maybe I'm mis-remembering, but I thought the main exit/entrance doors, the Galley doors, and so on, opened outwards. Saves room inside.

I don't have, nor fly, tubes at all, but I just looked. Default planes, and there were 5 I looked at, a very small percentage of all the commercial aircraft out there, I realize. All of them, the main exit/entrance doors open outward. Think about it folks...

 

 

Have a good time all.

Pat☺

A door has to be pulled towards the inside of the plane, and then pushed outward. The pressure on the door is easily 10-20 thousand pounds, so that makes it virtually impossible for a person to move.

That's right, I've seen a Flight Attendant struggle to open a door and have to call for help, it was too heavy or tightly closed for her to open on her own.

THat muscle you need to use is your brain.;)

depressurise, then open.:D

As ex Cabin Crew Instructor - it is absolutely true that it is virtually impossible to open an aircraft door in-flight due to the methods used during construction. Besides the pressure there are several huge bolts deployed when you close the door lever. Even on the ground in the old days we had to wait for the residual cabin pressure to release before the door could be opened. There was a very tragic incident involving a Saudia TriStar involved in an in-flight fire that returned to the departure airport and when it came to a halt on the runway, the doors couldn't be opened by emergency services from the outside due to this residual pressure in the cabin. Sadly everybody on board lost their lives due to smoke inhalation and of course the fire. So believe me don't ever worry about anybody trying to open the door on-board - they can't physically manage it, but they are restrained by Cabin Crew because of the fear they place on other passengers. Look up the Saudia Tristar incident it was in the 80's if memory serves me right, it's a really sad incident where even if the doors could have been opened everybody had died as the aircraft came to a stop.

Again this confirms my theory that (almost) nobody follows links. :rolleyes:

 

I left this out from the article:

Think of an aircraft door as a drain plug, fixed in place by the interior pressure. Almost all aircraft exits open inward. Some retract upward into the ceiling; others swing outward; but they open inward first ...

 

This of course would have saved PhantomTweak his question.

As ex Cabin Crew Instructor - it is absolutely true that tis it virtually impossible to open an aircraft door in-flight due to the methods used during construction. Besides the pressure there are several huge bolts deployed when you close the door lever. Even on the ground in the old days we had to wait for the residual cabin pressure to release before the door could be opened. There was a very tragic incident involving a Saudia TriStar involved in an in-flight fire that returned to the departure airport and when it came to a halt on the runway, the doors couldn't be opened by emergency services from the outside due to this residual pressure in the cabin. Sadly everybody on board lost their lives due to smoke inhalation and of course the fire. So believe me don't ever worry about anybody trying to open the door on-board - they can't physically manage it, but they are restrained by Cabin Crew because of the fear they place on other passengers. Look up the Saudia Tristar incident it was in the 80's if memory serves me right, it's a really sad incident where even if the doors could have been opened everybody had died as the aircraft came to a stop.

 

 

 

Do they have safety measures in place now since that terrible incident? I mean this was in the 80's! I can't imagine that nothing was corrected since then to prevent a tragedy like this from happening again.

I think you are all wrong! I hit SHIFT-E and the door opened right up!

:cool:

others swing outward; but they open inward first ...

Ok, now that makes sense! That explains my entire conundrum in a single sentence. :)

 

Now, one last question, if I may be so bold.

Did the cockpit crew dump the cabin pressure before DB Cooper to the LONG step off a short stairway? I can't even recall what altitude they were at when he took his leap. 10,000' MSL? Almost sounds like the military got the idea for HALO jumps from him.

 

I'm just wondering. Having said all that, were the aft doors (the tail doors?) in the 727, the plug type? Swing in a little then out? I went out several when we'd go to Hawaii every year, but darned if I payed any attention to how the doors opened. I was just happy that they did :D Of course, I was around 10 or 12 at the time, sooooooo...

 

Anyway, I didn't mean to stir up such a hornet's nest. I meant no offense to anyone, I just couldn't wrap my head around the logic of higher pressure holding a door closed, if it opened out. NOW I can, but at first... :confused:

 

By the way, I've seen some crash-crew trucks that have a "stinger" on a long boom. Designed to shove into a plane's cabin and spray a large volume of water very quickly. I imagine that, once it's shoved in, knowing how thin the cabin aluminum skin is, there's not enough of a seal around it to be air-tight, so the internal pressure, if any, will equalize, making it easy to open the doors from the outside. I don't know if it's standard equipment at all airports or not, and I doubt it is, but it seems to me it would have obviated the crew's inability to open the doors on the Saudia Tristar.

 

Have fun, all, and don't open any doors you shouldn't!

Pat☺

An update article.

 

 

By now, other passengers were scared. Hudek had raised the lever halfway up, according to the affidavit. Flight crew members would later tell the FBI agent that had the plane been flying at a lower altitude, the door could have opened.

 

https://www.washingtonpost.com/news/dr-gridlock/wp/2017/07/08/a-flight-attendant-smashed-wine-bottles-on-a-man-who-tried-to-open-the-exit-midair-fbi-says/

Whether doors can opened in flight depends on their designand the operating regime of the aeroplane. Pushing a door against air pressure from forward flight in aircraft like the C150 is going to be an effort, whereas opening a door inward like on many older transport propliners wouldn't be difficult at all. Military transports like the C130 Hercules regularly fly with open cargo hatches to enable drops or whatever, and Chinook helicopters use the open rear door as a gunnery position in recent service. There was also a case where one adventurous gentleman hijacked a DC9, stole a great deal of money, and jumped by parachute, officially never to be heard of again (recent evidence suggests he survived the jump only to die in the wilderness. His cache of money had been partially recovered from a river)

Pushing a door against air pressure from forward flight in aircraft like the C150 is going to be an effort,...

A sizeable friend of mine (6' 4", 260 lbs, not fat, literally stuffed into the cockpit) went on an intro flight in a C-152. On the way to the practice area the instructor banked to the left. Imagine my friend's surprise when his door popped open in flight. Nothing happened, my friend simply grabbed the door and slammed it shut. :-)

 

There was also a case where one adventurous gentleman hijacked a DC9...

D. B. Cooper hijacked a B-727.

 

peace,

the Bean