Hi,
Mike, thanks for your answer.
Originally posted by Mike
In simple terms (& depending on aircraft type) air is tapped off from the engines (& cooled as necessary) & enters into the aircraft. The aircraft has a maximum pressure differential permitted between the outside pressure (say at 35,000 ft) & inside (generally kept at about 6000 - 8000 ft for comfort). To prevent too much pressure building up in the aircraft, outflow valves are controlled automatically to keep the required cabin altitude
Mike, my question was related to all engines flame-out and APU off due to fuel depletion (I think you forget that). So the engines will not provide bleed air. That's why I was wondering how the aircraft will get air (for the ventilation) for the passengers at safe altitude (10,000 or 14,000 ft) mainly on Boeing aircrafts since they are not fitted with ram air scoop?
-What about Boeing ETOPS aircrafts (let's say 180 or 207 minutes): how the ventilation air will be provided to the all passengers during all this long diversion time ?(Usually chemical generator oxygen systems produce oxygen for 12-15 minutes, may be more few minutes for ETOPS aircrafts). Could the lack of ventilation air affect the health of passengers or provoke suffocation? It will be very helpful if someone can post the checklist of loss of thrust on both engines or loss of pressurization (or other checklist related to the subject mainly in ETOPS aircrafts like 757, 767, 777 that have longer diversion time).
-Consider we have now all engines flame-out at high altitude (BUT not caused by fuel depletion) and the APU is operating:
What you (as pilot) will do first ? (loss of thrust on both engines or loss pf pressurization checklist?)
Feedback very appreciated. Thank you in advance for your help.
Best regards.