View from an average 777 line pilot
Notes from an average B777 pilot. I feel deeply sorry for family and friends affected by this terrible situation. I have read most posts, 2000+.
1: Depressurisation without the necessary descent.
Leading to pilot incapacition sounds very plausible. Putting your mask on then checking your mate has his or hers on wastes time, maybe 5 to 10 secs. If you then find that the oxygen is not working game over, too late to descend the aircraft, your unconscious.
I have heard aviation doctors suggest that one pilot should use his useful conscious time, maybe only 5 secs to start the plane down to min safe altitude. The other puts on his oxygen straight away. If all goes wrong with donning the oxygen mask or supply at least the plane is going down and you might regain consciousness later at a lower level and hence regain control.
If the plane did depressurise and the crew were incapacitated why did it stay at a high altitude? Possibly the autopilot was working, because it flew at a high altitude and on a relatively steady westerly heading for maybe hours, using the best guess from primary radar and ACARS 30min radio pings! This suggest that the electrics were working in some way, but no transponder signals.
Seems too much of a coincidence, autopilot ok, transponder not, aircraft depressurisation and pilots not OK. Aircraft heading about west.
2: unlawful interference.
Timing perfect, just out of normal radio range, miles from land near a change of airspace. Transponder switched off, radio silence apart from some garbled messages. Military radar think they saw an aircraft flying west at FL295. ( Can't remember but I think all the 911 aircraft turned back with transponders switched off. So it's happened before. ) Plane eventually disappears. Did the pilots fool the hijackers or were the hijackers on their own and lost. Unfortunately I can't see a successful ditching being the outcome, because of the lack of ELT's etc.
Big problem with this theory, why didn't the few passenger phones that were almost certainly on, not get a signal over Malaysia or anywhere else. Not sure anyone would plan to bring jammers on board or confiscate every phone.
3: Note on transponder use.
We don't touch the transponder when busy.
When we do select a new code we just type in the new code,
NO switching to stby. When practicing Rapid depressurisation in the SIM it's very rare to see anyone select 7700, were just too busy. We turn of the airway or away from traffic, most pilots keep an eye on nearby traffic using TCAS. Some use look down on TCAS during emergency descent, it's force of habit from normal descents.
Last edited by Turkey Brain; 14th Mar 2014 at 02:51.
Reason: Too,wordy