Emergency Exit Doors Options

[richardreth]

I just read a crazy story of a passenger that attempted to open the emergency exit door aboard a commercial flight. I've never really thought about it, but i assume they are sealed and there would be absolutely no way anyone could either open one or even get close to opening one merely by messing with interior door releases ?
thanks!

[BMeister]

Hi Richard,

I too have thought about the exact same thing, ESPECIALLY WHEN I was onboard a B747 international flight, and some idiot parents let their kids sit on top of the emergency exist door, looking through the window (while in flight) and playing with the handle at 39,000, I could of slapped them both.


Now that I'm a pilot and working on my commercial i've learned more and asked a few questions about this,


This is what I understand from asking a few questions and using my flight education.


Air density at a higher altitude is less, which means air molecules are less dense outside at a higher altitude a pressureized aircraft is full of air density and air mocules which is more that what's outside,

an emergency exit must be unlached then pulled INWARD before you can open it outward, but because their is so much air in side the cabin compared to what's outside, it's hard to pull the door inward against the air pressure which is inside the fuselage

reading back what I wrote sounds complicated, ooops

Have a great weekend, I'd still like to learn more about this topic so will be watching.

[richardreth]

Hi Richard,

I too have thought about the exact same thing, ESPECIALLY WHEN I was onboard a B747 international flight, and some idiot parents let their kids sit on top of the emergency exist door, looking through the window (while in flight) and playing with the handle at 39,000, I could of slapped them both.
Now that I'm a pilot and working on my commercial i've learned more and asked a few questions about this,
This is what I understand from asking a few questions and using my flight education.
Air density at a higher altitude is less, which means air molecules are less dense outside at a higher altitude a pressureized aircraft is full of air density and air mocules which is more that what's outside,

an emergency exit must be unlached then pulled INWARD before you can open it outward, but because their is so much air in side the cabin compared to what's outside, it's hard to pull the door inward against the air pressure which is inside the fuselage

reading back what I wrote sounds complicated, ooops

Have a great weekend, I'd still like to learn more about this topic so will be watching.

Thanks BMeister, what you've explained actually does make perfect sense, the cabin is, of course, pressurized. Which i guess means the doors only open on the ground. So, let the kids play with them, and the crazies try to open them (?!)

[Piltdown Man]

The correct term is a "pressure differential". And how about some numbers. In the cruise, the typical cabin pressure differential is about eight pounds per square inch. So if the door was the size of an A4 piece of paper, the pressure exerted would be 700 pounds. So the pressure applied to the whole door is enormous. Moving the door handle would do very little other than to worry the drivers. So we needn't worry about this. What we do need to be concerned about are the plonkers who try to open the door. In general, we are too leneint on drunks and other goons who interfere with other passengers, cabin crew and aircraft in flight.

PM

[richardreth]

,,,Moving the door handle would do very little other than to worry the drivers. So we needn't worry about this. What we do need to be concerned about are the plonkers who try to open the door.,,,


Thanks so much PitdownMan, i had no idea the pressure was that great at cruising altitude. I'm a photographer/video shooter with well over a million miles in the air, and i've heard several stories about people messing with the emergency exits in-flight, but never understood the real mechanics of it. So, on my next flight if a drunk gets up and tries to open an exit, it's not so much like, go ahead and try, it's more like, you'll never get it open. The real danger, as i understand you to say, is that this individual is out of his mind and could pose a bigger threat.

[The Airbuser]

Works also with the cockpit windows...

In some airplanes like the MD-80 series, the cockpit windows are secured to the frame from the inside, so the differential pressure works as a backup in case the bolts fail.

Then again, some other aircrafts don't have this type of "system", like the F100 if I'm not mistaken, right PM?

Ed

[Aspiring Boeing ...]

I think I know where you're coming from Airbuser. The Boeing’s do have this "system", which works when the bolts are removed/ moved. But just one thing... What does the automatic system do? You always hear the pilot say "cabin crew, doors to automatic". What is that about then?

I completely understand PM's point about pressure differential, and the system is used as safety on the Boeing family and the Airbuses. But some aircraft don't, like the DC-10, or is this only the case with the cargo doors? Oh, and speaking of those, the 747, 757and 767 cargo doors open outwards (not sure about the 777 or 787).

I remember reading about the topic being discussed. It was a First Choice 767 flight to Cuba. Still, it does worry you when a drunkard is tolerated and tries to do crazy things that just could cause loss of life or damage to an airplane.


Regards,
Chris

[Ranger]

Cargo doors are not generally accessible from the inside of the aircraft by it's occupants. The DC-10 passenger doors are designed the same as the doors on all passenger airplanes. They rotate inward and then close outward to provide a postitve seal that is quite literally impossible to break in flight with positive pressurization.

[The Airbuser]

But some aircraft don't, like the DC-10, or is this only the case with the cargo doors? Oh, and speaking of those, the 747, 757and 767 cargo doors open outwards (not sure about the 777 or 787).

As far as I know every (or almost every) aircraft doors, pax doors and emergency exit doors that is, open the same way as Ranger described above.

Then again, some manufacturers design the cargo doors to open outward instead of inward, to allow more cargo space, and since you mentioned the DC-10, I'll assume you've heard the problems the DC-10 had with it's cargo doors when it had little time in service. Same as it happened to the B747. However, on DC9 series, the only pressurized cargo hold is the number 1, the forward-most hold in the airplane. Not knowing the DC-10 nor the B747, I could not give you an absolute answer, since those airplanes can carry containers and pallets on their holds, I think that part of the airplane is pressurized too.

Ed

[rjb4000]

But just one thing... What does the automatic system do? You always hear the pilot say "cabin crew, doors to automatic". What is that about then?

Slides? If a door is armed and opened the slide is inflated - if it's disarmed it can be opened normally.

[AirRabbit]

Slides? If a door is armed and opened the slide is inflated - if it's disarmed it can be opened normally.

You're correct rjb ... and with those doors that open into the ceiling, the automatic mode also allows the door to be opened much more quickly - usually by a bottle of compressed gas that literally blows the door into the open position, extracting the slide or slide/raft as appropriate.

Oh, and by the way - the voice that you hear saying "Doors to automatic" isn't usually the pilot - it's usually the Senior Flight Attendant - or at least the F/A performing those duties at that time.

[Davidc]

Surely if you throw the emergency door outward (however low altitude the a/c is flying) it could possibly damage the tail- wing, elevators, and maybe rudder which is essential to control the a/c. Should it even be opened in midair given any circumstances or only opened once on water or land?

I might be wrong in saying that it is thrown out.

Can someone please clear this up for me

[Ranger]

Surely if you throw the emergency door outward (however low altitude the a/c is flying) it could possibly damage the tail- wing, elevators, and maybe rudder which is essential to control the a/c. Should it even be opened in midair given any circumstances or only opened once on water or land?

I might be wrong in saying that it is thrown out.

Can someone please clear this up for me

First, ask yourself why you would EVER open any door on an airliner in flight? That isn't even trained when crews go through emergency evacs. Second, if the doors can be accessed by the occupants of the aformentioned aircraft, they open INWARD toward the cabin. Since that's how they are designed there is no way (unless the differential pressure is zero) that they can be opened in flight. Since this is all true there is no worry about damage to control surfaces.

[SF3aviatrix]

if the doors can be accessed by the occupants of the aformentioned aircraft, they open INWARD toward the cabin. Since that's how they are designed there is no way (unless the differential pressure is zero) that they can be opened in flight.

This is true of almost every door on planes like Boeings, Airbuses ect.

However, there are a few exceptions. The entry door on the Saab 340 is not a plug type and actually opens outward. During flight it is secured by a metal locking bar that keeps the cabin pressure from blowing it open. If the locking pin on this door doesn't line up with the markings, we don't go as it can't be verified as safely locked.

In fact, the B1900 is the same way and at least one has opened inflight.

[chris_pilot]

Works also with the cockpit windows...

In some airplanes like the MD-80 series, the cockpit windows are secured to the frame from the inside, so the differential pressure works as a backup in case the bolts fail.

Then again, some other aircrafts don't have this type of "system", like the F100 if I'm not mistaken, right PM?

Ed

Yep. Makes more sense to do this as fitting them from the outside pretty much guarantees a window blow out in the rare event of mulitple bolt failures.
Flight BA5390 comes to mind. An engineer fitted the said windscreen with 90 retention bolts too small in diameter. He looked at the bolts he was replacing (already the wrong size from last fitting) and compared them to others, visually choosing the bolts instead of checking the technical specs - an almost fatal mistake. The outside pressure proved to much and the window blew sucking the pilot out of the window up to his waist... Makes for an interesting read.

Cheers,
Chris

[Aspiring Boeing ...]

As far as I know every (or almost every) aircraft doors, pax doors and emergency exit doors that is, open the same way as Ranger described above.

Then again, some manufacturers design the cargo doors to open outward instead of inward, to allow more cargo space, and since you mentioned the DC-10, I'll assume you've heard the problems the DC-10 had with it's cargo doors when it had little time in service. Same as it happened to the B747. However, on DC9 series, the only pressurized cargo hold is the number 1, the forward-most hold in the airplane. Not knowing the DC-10 nor the B747, I could not give you an absolute answer, since those airplanes can carry containers and pallets on their holds, I think that part of the airplane is pressurized too.

Ed

Yes you are correct, I have herd several stories on air crash investigation. The problem occurred twice in two years, and the plane had just started service. The first accident involved an American Airlines DC10, and the second involved a THY Turkish Airlines DC10. Convair warned that the locks were not very good and as the doors (cargo) opened outwards, they had to withstand a large pressure differential. Apparently the locks were not capable, so the FAA ordered the airworthiness directive. It did state what many of you have said; that Boeing uses an inward opening door so that the pressure acts as a lock also. However the 747 cargo doors open outward - but the locks are strong enough to hold - unless the motor shorts out and tries to open the doors, as with the United incident on the flight from Honolulu.

Regards,
Chris

[bluebird121]

I just read a crazy story of a passenger that attempted to open the emergency exit door aboard a commercial flight. I've never really thought about it, but i assume they are sealed and there would be absolutely no way anyone could either open one or even get close to opening one merely by messing with interior door releases ?
thanks!

Was this the incident or is this another one ? This is the link for it complete with a video of their arrest:
http://news.bbc.co.uk/2/hi/uk_news/7530239.stm

Women arrested after flight
A passenger captures the moment when two British women were arrested by German police after trying to open a cabin door mid-flight.

The women were held in their seats by security staff until the plane, which was flying from the Greek island of Kos to Manchester made an emergency landing in Frankfurt.

An airline spokeswoman claimed the women had been drinking heavily and were abusive towards cabin crew.

[Aspiring Boeing ...]

Was this the incident or is this another one ? This is the link for it complete with a video of their arrest:
http://news.bbc.co.uk/2/hi/uk_news/7530239.stm

No, this is a different one. I think that richardreth was referring to a First Choice Airways incident which happened over Bermuda en route to Cuba. I read it in the newspaper; I am imagining that this is where richardreth may have seen it also.

Your link shows how much we need to clamp down on this discusting behaviour. After all, they drink too much and then the airline has to pay out for landing fees etc. We need to start making an example of people and shame them, and ensure alcohol is sold properly, so that they can't get drunk enough to go wild. Of ciurse, there will always be one looney who gets grump on when he or she isn't drunk. They should start banning these people from flying, as they are a threat to peoples safety and, quite frankly, I would not want to listen to that when on my way to or from my holidays.

Regards,
Chris