SA-JET From South Africa, joined May 2000, 297 posts, RR: 0 Posted (13 years 2 months 2 weeks 4 days 22 hours ago) and read 2731 times:
I have heard of procedures for B747 (well, any plane I guess) to evac dense smoke from the cabin in mid-flight is to "open" cabin doors? When I say open-apparently the crew swing the door handle to such a position that it only opens the pressure seals or someting like this? (after decompressing the cabin I guess)
Is it true, or just some rumour going around? (this Q ties in with another one on the forum about the ram air generator(?) being used to ventilate the cabin in such an emergency.
H. Simpson From United States of America, joined Mar 2001, 949 posts, RR: 2
Reply 1, posted (13 years 2 months 2 weeks 4 days 17 hours ago) and read 2687 times:
When I saw the topic I was thinking the same thing too - open the doors. I'm not a professional, but I think the pilot will descend down to a safe altitude (say 10,000 ft, pressure difference is not that much as FL390) before opening the doors for ventilation.
Duncan From United States of America, joined Apr 2002, 131 posts, RR: 0
Reply 2, posted (13 years 2 months 2 weeks 4 days 17 hours ago) and read 2669 times:
Yes, quite correct.... the airplane descends to 10,000ft or less and opens the door a crack. I worked with the guy who designed the system on the 757. There is a special retainer that goes on the door handle which only allows the door to be opened by so much. Since he was the designer he was 'asked' to test his own design. They flew the a/c below 10,000ft, strapped him in a harness attached to the seat tracks and made him open the door. He says the noise was horrendous. He opened the door, installed his device and watched. I can imagine that wold be quite a rush (literally)
I assume there are other such similar systems on other models.
Mr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 8
Reply 4, posted (13 years 2 months 2 weeks 4 days 15 hours ago) and read 2657 times:
If the pilots of a Saab 2000 have smoke in their cockpit, would one of the emergency procedures be to open the little round door that's located below the cockpit's left side windscreen? What is this door's actual purpose? (other than for a McDonalds drive-through).
AJ From Australia, joined Nov 1999, 2404 posts, RR: 24
Reply 6, posted (13 years 2 months 2 weeks 4 days 13 hours ago) and read 2622 times:
On the 747-400 you can activate the smoke handle on the overhead panel to evacuate smoke from the flightdeck, or open doors 2 and 4 (from memory) to suck smoke out of the cabin. On the 767 the outflow valves are opened to suck the smoke out.
Mandala499 From Indonesia, joined Aug 2001, 7408 posts, RR: 78
Reply 8, posted (13 years 2 months 2 weeks 3 days 16 hours ago) and read 2529 times:
If this is too long, don't bother reading it !
Open the doors ???? I think they'll have to try the smoke in cabin/cockpit procedures FIRST before trying anything like that...
Here's the procs for 737-200 for evacuating smoke...
Concentration of smoke requires it's removal from the passenger cabin and/or cockpit.
OXYGEN MASK AND REGULATORS -> ON, 100%
SMOKE GOGGLES (if required) -> ON
COCKPIT DOOR -> CLOSE
CREW COMMUNICATION -> ESTABLISH.
A.1. If Packs are OFF and smoke source is confirmed in the cockpit:
A.1.a Establish Normal Holding Airspeed (High airspeed may prevent opening the window)
A.1.b First Officer's sliding window open (Smoke flows out through the First Officer's sliding window)
A.2. If packs are ON and smoke is confirmed to be in the cockpit or main cabin:
A.2.a Pressurisation Mode Selector -> Standby
A.2.b Cabin Altitude Indicator -> Increase (Max 10,000ft)
Select higher cabin altitude to increase the ventilation rate
A.2.c Cabin rate selector -> Maximum Increase (select approximately 2000fpm)
A.2.d L & R Packs switches -> verify on
A.2.e Engine thrust -> minimum 1.2 EPR (this provides maximum ventilation)
A.2.f Cockpit Aircon and Gasper outlet -> Open (this ensures adequate air flows through the cockpit)
B. If Smoke Is Uncontrollable
B.1.a Airplace Altitude -> Lowest Safe Altitude or 10,000ft whichever is higher
B.2 At 14,000 ft or below
B.2.a Pressurization Mode Selector -> Man AC
B.2.b Outflow valve switch -> Open (Position outflow valve to FULL OPEN. This causes the cabin airflow to carry smoke aft)
This implies opening the cabin door as a last resort will only be done at LSALT/10Kft or below (depending on situation) and at holding speeds... Open windows or doors at high speeds = trouble.
When losing situational awareness, pray Cumulus Granitus isn't nearby !