# Opening an exit door at 35,000 feet **URL:** \ **Category:** Factual Questions\ **Created:** [March 6, 2018, 6:03pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131 "2018-03-06T18:03:21Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [March 6, 2018, 6:03pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/1 "2018-03-06T18:03:21Z")
I was under the impression that it was really hard, if not impossible, for someone to open an exit door of a commercial aircraft at cruising altitude due to the pressure differential. I figured that if it was easy to do then lots of unstable people would be doing it and causing havoc on commercial flights. Is what I believe in fact true? ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 6, 2018, 6:11pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/2 "2018-03-06T18:11:36Z")
> [@dolphinboy](#): > > I was under the impression that it was really hard, if not impossible, for someone to open an exit door of a commercial aircraft at cruising altitude due to the pressure differential. I figured that if it was easy to do then lots of unstable people would be doing it and causing havoc on commercial flights. Is what I believe in fact true? The trick is that the door opens inwards, so in order to open it at altitude, you’d have to fight against all the air pressure inside the plane. So, yes, I suppose you believe correctly, if I’m parsing your post right. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 6, 2018, 6:16pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/3 "2018-03-06T18:16:34Z")
Yeah, it’d take a few tons of force to pull the door in. Though I suppose that you could, in principle, do something to depressurize the cabin first. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [March 6, 2018, 6:30pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/4 "2018-03-06T18:30:32Z")
> [@](#): > > At a typical cruising altitude, up to eight pounds of pressure are pushing against every square inch of interior fuselage. That’s over eleven hundred 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 From [here](http://www.askthepilot.com/questionanswers/exits/). (Of course, if the woman really was God, maybe she could have done it.) ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [March 6, 2018, 8:39pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/5 "2018-03-06T20:39:51Z")
> [@Chronos](#): > > Yeah, it’d take a few tons of force to pull the door in. [27,000 to 28,000 pounds, apparently](https://boards.straightdope.com/sdmb/showthread.php?t=832446). ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 6, 2018, 9:46pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/6 "2018-03-06T21:46:19Z")
They’re called ‘plug doors’, and from my google searches, it appears that ‘all or most’ modern commercial aircraft use them - implying that some perhaps don’t (or recently didn’t) - and relied upon outward opening doors where the strength of the locking mechanism was critical to keeping it shut. Can’t find an example of that though ---
**Author:** ![snfaulkner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snfaulkner/32/433_2.png) [@snfaulkner](https://boards.straightdope.com/u/snfaulkner)\ **Post date:** [March 6, 2018, 10:05pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/7 "2018-03-06T22:05:16Z")
This feels like a “Need answer Fast” type situation. ---
**Author:** ![Heracles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heracles/32/487_2.png) [@Heracles](https://boards.straightdope.com/u/Heracles)\ **Post date:** [March 6, 2018, 10:18pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/8 "2018-03-06T22:18:51Z")
> [@Darren\_Garrison](#): > > From [here](http://www.askthepilot.com/questionanswers/exits/). > > (Of course, if the woman really was God, maybe she could have done it.) For those (like me, a minute ago) who don’t know what this is about: [a lady tried to open a door on a U.S. domestic flight while screaming “I am God”](http://www.dailymail.co.uk/news/article-5467755/Passenger-takes-woman-trying-open-cabin-door-flight.html). ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 6, 2018, 10:24pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/9 "2018-03-06T22:24:06Z")
“All or most” sounds to me like “probably all of them, but we can’t track down every model of airliner used anywhere in the globe, so we’ll hedge our bet”. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [March 6, 2018, 10:41pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/10 "2018-03-06T22:41:47Z")
> [@Chronos](#): > > “All or most” sounds to me like “probably all of them, but we can’t track down every model of airliner used anywhere in the globe, so we’ll hedge our bet”. If my memory serves me correctly (and it’s been know to be treasonous) … there was an incident involving a cargo bay coming off at altitude … and the FAA mandated the replacement of all doors that could come off … so we’re in the process of replacing … not all of them right now, but someday it will be … ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [March 6, 2018, 11:21pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/11 "2018-03-06T23:21:30Z")
It’s worth remembering that it’s a lot of extra work to design a pressurized plane that _doesn’t_ use plug doors. Plug doors are present on essentially all pressurized aircraft because they’re the most structurally efficient way to put a door in a pressure vessel. It would take extra money and effort to design a conventional door that sealed as well as a plug door. Even then, fuselages with non-plug doors are inherently weaker than ones with plug doors, so pressurized planes without plug doors are reinforced (and so heavier) to achieve adequate strength. The linkages needed to allow a plug door to open outwards are complex and add weight, but not as much as a plug door saves in structural reinforcement. Cargo doors often use a non-plug design simply because the space inside is so valuable. Plug doors open inward, and the space required to open the door means less carried, which in turn means the plane is more expensive to operate. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 6, 2018, 11:39pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/12 "2018-03-06T23:39:42Z")
There could also be some commercial aircraft which aren’t pressurized (either because they fly low enough not to need pressurization, or because they’re carrying non-pressure-sensitive cargo), which might have some other door type. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [March 6, 2018, 11:46pm UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/13 "2018-03-06T23:46:20Z")
The talk of plug doors makes me think of the windows used in pressurized aquariums for deep-sea creature and on deep-sea submarines, which are [thick cones held sealed by the water pressure](https://www.wired.com/2012/06/st_abyssbox/). ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [March 7, 2018, 12:02am UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/14 "2018-03-07T00:02:24Z")
> [@Mangetout](#): > > They’re called ‘plug doors’, and from my google searches, it appears that ‘all or most’ modern commercial aircraft use them - implying that some perhaps don’t (or recently didn’t) - and relied upon outward opening doors where the strength of the locking mechanism was critical to keeping it shut. > > Can’t find an example of that though I do not believe that the main passenger door on the Bombardier regional jets operate on a plug basis. They open up and out. Perhaps one of our pilots can offer information on how those doors are prevented from opening in-flight. ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [March 7, 2018, 12:20am UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/15 "2018-03-07T00:20:08Z")
> [@](#): > > At a typical cruising altitude, up to eight pounds of pressure are pushing against every square inch of interior fuselage. That’s over eleven hundred 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. That would imply that the pilots have to equalize the pressure for wherever they’re landing at (LA vs. Mexico City say), or the doors cannot be opened. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [March 7, 2018, 12:42am UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/16 "2018-03-07T00:42:26Z")
[It typically happens automatically](https://aviation.stackexchange.com/questions/26283/how-does-the-cabin-pressure-controller-work-in-a-large-commercial-airliner), but yes, the pressure must be equalized between the cabin and the ambient outside pressure. But an aircraft isn’t airtight like a champagne bottle…it’s more like a well-sealed aluminum sieve. Bleed air from the engines is (usually) used to continually add pressure, while imperfect seals and outflow valves release it. Of course, the commercial pilots on this board may have a lot more to add. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [March 7, 2018, 1:03am UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/17 "2018-03-07T01:03:24Z")
Just a quick note of clarification: bleed air is usually used to continually add pressure to the cabin. But the Boeing 787’s engines don’t generate any bleed air, so it has electrically driven pumps to maintain pressure. I’ve heard some people claim that “the captain reduces the oxygen to keep the passengers docile,” which isn’t true. I didn’t want my sloppy phrasing to be read as supporting that claim. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [March 7, 2018, 1:38am UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/18 "2018-03-07T01:38:51Z")
You know what else had a plug door … Apollo 1 … ---
**Author:** ![Sunny\_Daze](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunny_daze/32/438_2.png) [@Sunny\_Daze](https://boards.straightdope.com/u/Sunny_Daze)\ **Post date:** [March 7, 2018, 2:05am UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/19 "2018-03-07T02:05:29Z")
It sounds like there is some risk involved. [Per this article](https://www.washingtonpost.com/news/dr-gridlock/wp/2018/03/06/i-am-god-a-woman-screamed-as-she-tried-midflight-to-open-a-planes-cabin-door/?utm_term=.546772376ef1) about the incident in the Washington Post, a passenger stated that > [@](#): > > “The pilot came on the loudspeaker and told us to ‘stop her at all costs’ from opening up the door.” Is there a mechanism at the door itself that allows equalization? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 7, 2018, 3:05am UTC](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131/20 "2018-03-07T03:05:50Z")
It might be that, even though it would be impossible for her to open the door, the captain didn’t know that (or wasn’t confident enough about it to risk the plane). It might also be that the captain judged that, if she tried and failed to open the door, she might instead switch to trying something else equally drastic, but which she had a chance of success at. [Next page](https://boards.straightdope.com/t/opening-an-exit-door-at-35-000-feet/810131.md?page=2)