Type-rated From , joined Dec 1969, posts, RR:
Reply 7, posted (10 years 4 months 2 weeks 5 days 16 hours ago) and read 14241 times:
The doors and emergency exits on most pressurized aircraft are really plugs. They are larger than the opening of the window/door and the internal pressure keeps them sealed nice and tight against the aircraft frame. I think the thought is that if a person is trying to open the door or window, what will they do for an encore!
Cyrillim From United States of America, joined Apr 2004, 35 posts, RR: 0
Reply 8, posted (10 years 4 months 2 weeks 5 days 16 hours ago) and read 14210 times:
Depending on the location of the door, the most the man could do is to crack the door open (with a lot of force) and depressurize the cabin. The door would not actually open all the way.
Certain exit doors on the 747 are designed for them to be opened in mid flight to release smoke should there be a fire in the cabin. This is only done at a lower altitude so I would imagine at 9000m the guy would have a pretty hard time trying to crack the door open. Kudos to the crew and passengers who managed to restrain this man.
Dl757md From United States of America, joined May 2004, 1562 posts, RR: 16
Reply 9, posted (10 years 4 months 2 weeks 5 days 16 hours ago) and read 14177 times:
I'm not sure if the 747 doors are equipped with flight locks like the 777 which lock the latches at airspeed above 80 knots. The 767 doors have no flight locks but the signal to unlock the door goes through the PSEU-Proximity Sensor Electronics Unit- which checks to see that door is actually closed before unlocking it. The PSEU may also look at the air/ground relay and determine not to unlock the door if the plane is in the air but I couldn't find anything about this.
Even if there is no flight locking procedure on the door at 30000 feet with a cabin altitude of 8000 feet(highest allowed) the pressure differential is about 6.5psid. The door is about 78 inches by 36 inches which is 2808 square inches. So the force pushing out on the door is over 9 tons! Remember the door opens inward off of the door stops before it goes up or out. Even the door emergency assist system wouldn't be able to overcome this amount of force.
Now lets talk about the "upper and lower gate"(747) say 4"X36"=144 square inches which @ 7psi is 1008 pounds so the linkage will have to be able to withstand 1000 pounds just to "crack" the upper and lower gates and that's 1000 pounds for each gate. Now if the mechanical advantage is there to open the gates this will not depressurise the A/C as the outflow valves can accommodate a leak of this size as each is around 288 square inches, even so if the leak was anymore the A/C would only slowly depressurise and the crew can take action and be below 14,000' in a few minutes.
Travelplus From United States of America, joined Nov 2004, 47 posts, RR: 0
Reply 16, posted (10 years 4 months 2 weeks 5 days 9 hours ago) and read 13375 times:
Why would someone even think to open such a door? I mean come on did this guy drink too much Hooch Vodka that would cause him to try to do such an act? I mean even a 5 year old knowes not to open such a door? Is this guy Autistic with a comorbidity of Mental Retardation? I'm glad the flight attendants tried to stop him. This guy deserves a long prison sentence unless he's Bipolar. Come one why would you board the plane if your so insane?
CCA From Hong Kong, joined Oct 2002, 876 posts, RR: 14
Reply 18, posted (10 years 4 months 2 weeks 5 days 7 hours ago) and read 12784 times:
If smoke/fumes severe and smoke source determined to be in the cabin:
LANDING ALTITUDE SWITCH................. MAN
LANDING ALTITUDE CONTROL..................... SET 8000-8500 FEET
Set landing altitude between 8000 and 8500 to command cabin altitude to 8,000 feet.
EQUIPMENT COOLING SELECTOR.... NORM
Level off at the lowest safe altitude or 8,500 feet, whichever is higher.
OUTFLOW VALVE MANUAL SWITCHES..................................................ON
OUTFLOW VALVES MANUAL CONTROL.............................................. OPEN
AIRSPEED........................ 200 KIAS OR LESS
DOORS TO BE OPENED............ DETERMINE
If smoke/fumes concentration determined to be in the forward section of the cabin, a Door 1 or 2 and a Door 4 or 5 must be opened.
If smoke/fumes concentration determined to be in the aft section of the cabin, open a door 2 only.
Direct personnel to open door(s). Position mode selector handle to MANUAL and rotate and secure handle in the 12 o’clock position.
When smoke/fumes evacuated: Direct personnel to close door(s).
Position mode selector handle to AUTO. The forward door must be closed before closing the aft door.
Gary2880 From , joined Dec 1969, posts, RR:
Reply 19, posted (10 years 4 months 2 weeks 5 days 6 hours ago) and read 12384 times:
this is one of the main reasons why i hate flying, i like to sit as far from the emergancey exits as possible, when i do have to fly i keep my eye on the person at the exit door just incase they try anything funny or are mentally loopy, the 1 thing that really scared me about flying is if someone trys to open the door *shudder*
PilotGirl From Canada, joined Nov 2004, 13 posts, RR: 0
Reply 21, posted (10 years 4 months 2 weeks 5 days 2 hours ago) and read 11248 times:
There was an incident, perhaps 5-10 years ago, of a BA 747 climbing out of Heathrow or Gatwick. One of the main passenger door handles started moving by itself - as if to open the door. Presumable some odd reaction with the settling air pressure. The flight crew called the BA engineers, who explained it was impossible for the door to open.
The FAs were so freaked out about it that, despite the reassurances of the engineers, that the 747 ended up dumping its entire fuel load and returning to the airport.
I never saw anything further about the reason for the door handle moving. As far as it seemed at the time they confirmed no fault on the door.