PDA

View Full Version : Opening emergency exit !


josh121.5
27th May 2011, 16:04
1. Is it possible for a passenger to open the Emergency Exit door during flight or does the captain/cabincrew have to authorize a switch first before someone can open it ?

2. what exactly is arming and disarming of cabin doors ??

thnx in advance for the reply guys !!!

wowzz
27th May 2011, 21:37
Why do you want to know this!

SloppyJoe
27th May 2011, 22:43
Honestly who cares why he wants to know, he is aking either because he wants to open one in flight or out of curiosity. Either way no harm can come from explaining and all this can be found online, not an industry secret.

No you normally can not open a door in flight. The doors in the cabin are plug type door so they have to come into the cabin slightly before being rotated outwards. When the aircraft is pressurized you would not be strong enough to overcome the forces as would have to pull the door in against the pressure. If there is a decompression then yes you could open a door.

When the door is armed the emergency slide should auto inflate if the door is opened from inside the cabin. If it is disarmed it should not inflate when opened from the inside. If opened from the outside this action should also disarm the slide. There is also a handle to manualy inflate the slide if it does not inflate and you need to use it.

Cargo doors are not plug type but have multiple locks holding them in place. I think all incidents where doors have opened in flight of modern airliners have been cargo doors where the locks failed.

You will however get in lots of trouble and arrested if you are seen trying to open a door in flight, which you can't do anyway.

EW73
28th May 2011, 04:12
At least on 747s opening the 'armed' doors from outside will not blow the slide.

On a B737, opening the 'armed' door from either inside or outside will blow the slide.

Also, the overwing exits are automatically locked when the airplane is off the ground, the pilot gets an indication if this is not the case.

Also, if you are 'lucky' enough to be the one to open one of the overwing exits on the ground, as the FA brief tells you, "open the cover and simply pull the red handle, and the door will open automatically", what they don't tell you is, when you pull that red handle, the door opens very quickly, so make sure you let go of the red handle or you will go out the exit with the door, i.e. very quickly!

:ooh:

josh121.5
28th May 2011, 04:34
TEXT Speak - Save it for your Mobile - English in here please.

Avionker
28th May 2011, 12:07
@ SloppyJoe

I think all incidents where doors have opened in flight of modern airliners have been cargo doors where the locks failed.

I could be wrong but I seem to recall that all the incidents of cargo doors opening in flight have occurred as a result of the latches not been fully engaged.
This was due to the doors not been correctly rigged. A failure of maintenance procedures, as opposed to design or equipment failure. A little pedantic perhaps but quite an important distinction, in my opinion at least.

Not an issue on the 737 or MD-80 as those aircraft have inward opening cargo doors.

Blink182
28th May 2011, 22:37
United 811

747 cargo door opened in flight due to electrical short circuit.Not a maintenance error , but a design failure.

9 fatalities.

Di_Vosh
29th May 2011, 01:49
incidents of cargo doors opening in flight have occurred as a result of the latches not been fully engaged.

This was due to the doors not been correctly rigged. A failure of maintenance procedures, as opposed to design or equipment failure.

But if you've got a cargo door that can be incorrectly latched, or incorrectly "rigged" then that in itself is a design failure.

Avionker
29th May 2011, 08:49
@ Blink 182

I had forgotten about that one, I stand corrected, thank you.

@ Di_Vosh

All flying controls can be incorrectly rigged. All doors can be incorrectly rigged. Every moving piece of an aircraft which must be installed and subsequently adjusted to within certain parameters, can be incorrectly rigged. By your definition every aircraft in service has hundreds if not thousands of design failures.

To my mind a design failure is something which makes a component or system, when installed correctly, unfit for it's intended purpose. What is your definition exactly?

If a component is correctly installed, adjusted and all all necessary locking devices in place (lock wire, cotter pins etc.) how can that be a design failure?

I accept that in an ideal world everything would indeed be fool-proof but the world we live in is, as you know, far from ideal. That's why it's up to guys like you to fly the aircraft within design limits, and for us to maintain and repair aircraft in accordance with the procedures and limits defined by the manufacturers.

WHBM
29th May 2011, 15:47
I could be wrong but I seem to recall that all the incidents of cargo doors opening in flight have occurred as a result of the latches not been fully engaged.
This was due to the doors not been correctly rigged. A failure of maintenance procedures, as opposed to design or equipment failure. A little pedantic perhaps but quite an important distinction, in my opinion at least.
The most notorious case was the initial DC-10 cargo door, which led to multiple blowout failures culminating in the loss of the THY aircraft at Paris with all on board.

Although the ground crew had mishandled the operating mechanism, it was recognised this was all too easy to do with the rigging employed. In fact the rigging design was subsequently used in engineering training courses as an example of "would any idiot design one like this, then", done anonymously, and then revealed for what it was at the end of the exercise.

NWA SLF
30th May 2011, 00:54
Wasn't it a Saudia L-1011 about 30 years ago where the plane had a major fire, landed safely, but the flight crew either didn't de-pressurize the cabin or release the emergency doors so they couldn't be opened and everyone inside (over 250) died of smoke inhalation? As I recall it sat on the end of the runway for over 15 minutes before a door popped open. But I remember a KLM flight attendent giving special instructions to us exit row passengers one time telling us not to pull the door release handle just to test things out or she would have a day's paperwork to fill out.

EEngr
30th May 2011, 02:55
@Avionker


To my mind a design failure is something which makes a component or system, when installed correctly, unfit for it's intended purpose. What is your definition exactly?
When the failure of a component or system leads to a hazardous condition.

Things fail. System designs need to take this into account. In the case of United 811, the system had a failure mode where a short circuit resulted in the uncommanded unlatching/opening of a cargo door in flight rather than tripping a c/b or otherwise leaving the system in an inoperative but otherwise safe state.

yotty
30th May 2011, 11:00
On the B777 the elec bus which powers the cargo doors is not live when the a/c is in the air. Quite sensible really! ;)

Avionker
30th May 2011, 12:05
Nor is it on the 747 yotty, which is another piece of the puzzle if you read the accident investigation report into the incident.

In fact a read of the report shows that there were several factors at play, poor design, poor maintenance, poor oversight by the FAA. No one walks away looking particularly good except the crew, whom it must be said, did a fantastic job recovering the aircraft safely.