Can an Airplane Door Open in Midflight?

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posted on Jun, 8 2013 @ 11:41 AM
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Have you ever wondered how serious a threat it really is for someone to open a cabin door in mid-flight? Many stories in recent years cite passengers with a screw loose, attempting to do just that. They seem either to want to jump out or bring down the plane. So..... Can it be done? Well, National Geographic wrote a little piece to try and address that question.


Is it possible for a passenger to open the door of a commercial jet while it is in flight?

We're talking about a pressurized airplane, where the internal cabin is at a higher pressure than the outside. The internal pressure is forcing the door outward against the seal. [To open the door] you have to pull the door inward. Because of the differential [difference in] air pressure, it's beyond the capability of a human to do that - they're not strong enough. It's probably 6 p.s.i. (pounds per square inch) of differential pressure against hundreds of square inches of door. So that means it would be something like a thousand pounds you'd have to pull in.


That's reassuring. Can't be done! That also tends to make some sense in not only how they explain it, but how and why it would be designed that way. It builds in a fail safe by sheer natural forces that I'd imagine wasn't thought to be needed for countering crazy humans at the time it was made.

What about DB Cooper? He jumped from an airliner in flight, right? Well.. Yes.. He did. In that infamous robbery case, he bailed out of the plane he robbed, never to be seen again. However.....not the same issue.


Yes, he had the guy depressurize the plane. That was the only way he was able to do it. Since that time, the FAA [Federal Aviation Administration] has mandated that the manufacturers disable those doors [the door at the back of the plane that Cooper used; jumping from a side door could mean hitting a wing or engine]. They have a "D.B. Cooper Switch"—that's what they call it—that disables or locks those doors when the [landing] gear is up.
Source

So, there you have it. The story goes on with more on the topic and I'd recommend popping over to give it a look. However, next time you hear someone say 'That was a close one!' to a story of a passenger being restrained from opening a cabin door, in-flight? You can confidently state the plane was never in any danger because you know the physics behind why it's not possible without major malfunction or flight deck cooperation.




posted on Jun, 8 2013 @ 11:49 AM
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Thanks very interesting post. And thanks for answering one of the thousands of questions that's been lurking around in my pea brain all these years



posted on Jun, 8 2013 @ 12:06 PM
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reply to post by Wrabbit2000
 


Interesting you might like this though it is not the door it is really an amazing tale that you might want to add to your thread, in 1972 a DC9 airliner exploded in flight at 33,300 feet and an air hostess by the name of Vesna Vulovic was blown out of the exploding aircraft, she survived and landed in a snow bound forest in the former Yugoslavia.

Here is an old report about a woman whom was sucked out of a plane door on a corporate flight.
abcnews.go.com...
Now sadly she did not survive.
I also remember another story in which a air hostess tried to secure a door whose door latches she noticed were not correctly fastened and it blew out, she then fell out at about 10,000 feet over Scotland, she landed in a pine forest and the branches broke her fall similar to the first account, she suffered a broken collar bone, scraped and bruises, the plane made an emergency landing. I remember this from the 1980's but can not find anything on the net though she gave an interview on good morning television some time later.



posted on Jun, 8 2013 @ 12:31 PM
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reply to post by LABTECH767
 


Thank you very much for the addition to the thread. I'm just imagining that last one where she lived by falling through the branches. Just think of the looks on the flight crew's faces if they'd seen her come walking up, not having been told she survived the experience. Now for the horror of what she endured, THAT aspect could sure be fun for her, eh? See how fast people can go white as a bed sheet. lol.... It's amusing only because she did survive with minor injuries of course.

I suppose those fall under the category of malfunction or catastrophic malfunction, and definitely set the exceptions to the rule. It's always interesting to see those as well. That's a great addition to the OP material.



posted on Jun, 8 2013 @ 12:50 PM
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reply to post by Wrabbit2000
 


Didn't DB Cooper jump mid flight?
Crazy if you ask me.

ETA: I see you addressed that in the OP. Apologies.
edit on 8-6-2013 by JayinAR because: (no reason given)



posted on Jun, 8 2013 @ 01:06 PM
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reply to post by Wrabbit2000
 


Thanks Wrabbit.. It is reassuring to know that a someone with a screw loose cannot open the door on a plane.. I have a friend that always sits at the back of the plane. He thinks its safer because if planes go down they can nose dive.. I do not know if it really makes a difference or not though..



posted on Jun, 8 2013 @ 01:24 PM
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reply to post by purplemer
 


They've done studies in that regard.
If I remember correctly, you are "safest" in the middle of the plane. The tail section is often torn off in those circumstances.



posted on Jun, 8 2013 @ 02:53 PM
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Several decades back, a cargo door on the 747 could accidentally open on its own. That problem has been fixed.

United Airlines Flight 811 in 1989.

And again on the ground at JFK in 1991.

But these were open outward doors.



posted on Jun, 8 2013 @ 02:55 PM
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ahhhhhhh.....

One little catch to this law of physics (if it even is one)...

OK. So a normal plane is pressurized right? Well what is it pressurized to? Anyone know? I know from personal experience of flying that a KC-135 is pressurized to 8,000 feet. In fact, I believe that the highest we could pressurize the aircraft was for 10,000 feet so if your at or below that altitude, it doesn't take much to open the doors on a jet.

Here's a true story that some crew chiefs (zaphod) can attest to. One time a KC-135 landed and taxied to its parking spot. The outside elevation was at 911 feet (grand forks afb, ND). The aircraft remains pressurized until the co-pilot depressurizes the aircraft. At that time the boom operator opens the crew entry chute by pulling down on the open handle, allowing the door to swing down and open up. Pretty standard right?

Well on this occasion, the co-pilot and boom operator missed this part in the checklist, the boom proceeded to open the crew entry chute, and a lonely crew chief was there to assist in hooking up the latter for the crew to climb down. The chute blew off with so much force that it detached from the aircraft and struck the crew chief. Somehow he survived and the crew was brought to their knees because of a semi rapid decompression. Lesson learned.

Now we have the crew entry chute, the cargo door, two overwing hatches and an aft hatch on a tanker. They all have four point locking mechanisms on them that we have to check for every flight, before we pressurize the aircraft. On a tanker, the only thing I can think of happening in flight was the cargo door opening up in the pattern while doing touch and go's. But after the accident with the crew chief, pressure in the plane while doing pattern work (i.e. a boom's worse nightmare: touch and go's...so boring) was dropped to 2000 feet, in case of the same problem happening again.

Moral of the story: yes you can open up a door in a commercial airliner even if the jet is pressurized at 8,000 feet if you are in fact below 8,000 feet, because the pressure is even. We have all kinds of warnings in our T.O.'s about this. So if you see someone going for a door on descent or ascent, stop him please, and then come to ATS and tell us about it!

One point about a rapid decompression, a small hole in a plane will not cause an aircraft to lose pressure. We have a small hole in the boom pod that we used to smoke from (shhhhhh!!!!!). We created a contraption that held a cigarette in place in a position that sucked all the smoke out of the jet, thus the pilots up front couldn't smell it. Helped out us smokers on 15 hour OEF missions. lol

Also, the old nav sextant hole is still on the plane. there's just a little lever that you have to open up that reveals about a one inch hole to the outside of the jet that doesn't decompress the jet. So no a bullet hole won't cause it, but a bullet through a window might!



posted on Jun, 9 2013 @ 12:32 AM
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reply to post by boomer135
 


That sextant hole killed a guy one flight. He was doing the shot, and the window failed and pulled his head and shoulders through. The horrifying part was they were several hours out, and couldn't free his body. It took special tools on the ground to do it.



posted on Jun, 10 2013 @ 07:29 AM
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Originally posted by Wrabbit2000[/iWe're talking about a pressurized airplane, where the internal cabin is at a higher pressure than the outside. The internal pressure is forcing the door outward against the seal. [To open the door] you have to pull the door inward. Because of the differential [difference in] air pressure, it's beyond the capability of a human to do that - they're not strong enough. It's probably 6 p.s.i. (pounds per square inch) of differential pressure against hundreds of square inches of door. So that means it would be something like a thousand pounds you'd have to pull in.]


Not all aircraft doors are "plug doors" , the B777 and my current jet the B737 have "semi plug" type front and rear doors, while the overwing exits opens outwards.

The semi plug type doors can not be opened when the cabin is pressurized, and the overwing exits have flight locks activated at 80 kts at takeoff, and deactivated at the same speed at landing.

So, in modern jets doors can't be opened in flight no matter what type they are.



posted on Jun, 10 2013 @ 10:32 AM
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reply to post by Ivar_Karlsen
 


Thank you for that added insight. That adds a layer the National Geo article didn't get into and makes me feel even better about a nutjob not being able to make a sudden, unscheduled departure from a flight in-progress.


Different strokes for different folks and I am a believer in that ...as long as those types are stroking their nuttiness somewhere other than an aircraft outer door, right?

@ Boomer

I saw the same with a thing Mythbusters did about shooting through a plane window in flight. It took them forever to rig everything to work properly but they managed to pressurize an old fuselage in a plane grave yard to test it with. No matter what they tried for pressure differentials or holes, they couldn't get explosive decompression. Just an ugly hole with a stream of air blowing through it. I suppose that would be....horror move terrible if a human body part came to be across that hole and form the plug with different pressures to either side ...but as you note, the plane isn't going to come apart or passengers flying out at 30,000 feet if some nut job shoots a gun.

Unless they hit a control system of course, which would be my luck if I were on the plane. Oh yes. One shot. That's all it would ever take. Just one and if I'm on the plane? That ONE shot will surely hit the most critical item behind a wall or under the floor an airplane can possible have shot. That's just how Mr Murphy and I get along.

edit on 10-6-2013 by Wrabbit2000 because: (no reason given)



posted on Jun, 10 2013 @ 03:17 PM
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reply to post by Wrabbit2000
 


As interesting as that episode was, it was kinda of bittersweet for me. I flew interisland on that plane alot, and had to do plane search on it after 9/11 for several months (7 days a week). It was sad to see it destroyed like that, but at the same time it was an interesting death for her.



posted on Jun, 11 2013 @ 01:39 PM
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Originally posted by Wrabbit2000
No matter what they tried for pressure differentials or holes, they couldn't get explosive decompression.
Apparently all it takes is a mechanic using the wrong screws to fasten the cockpit windshield. It seemed to be secure until it popped off and tried to suck the captain out during the decompression. The flight crew struggled to hold the captain in the plane but thought he was dead because he was unconscious.

The same pressures that hold the doors shut also put tremendous strain on the windshield screws so using screws that are almost exactly the right size obviously isn't good enough.

British Airways Flight 5390



posted on Jun, 11 2013 @ 02:22 PM
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reply to post by Arbitrageur
 


The point they were after wasn't that they don't happen, but that they can't be caused by a bullet going through the aircraft side. You may be able to through the windscreen though. It's speculated that's what happened with the EgyptAir 767 that went down of the East coast.





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