Flight MH370 mechanical problems/fire/zombie plane theory?
"Caught fire. The pilots, thinking it was an electrical fire, turned off all electrical systems they could. (Worry about fire is one reason they CAN turn off everything, including the radios.) Then they turned west toward the nearest major airfield, to try to make an emergency landing.
Unable to put out the fire, they climbed to extreme altitude because the low oxygen content of thin air (there is as much oxygen, percentage-wise, but less air in total, so less oxygen) reduces the intensity of fire and would help put it out. The problem is that to do this they climbed higher than the plane was normally meant to fly, and when you get that high the air is so thin that the stall speed (the speed below which there isn't enough airflow over the wings to keep flying) starts to get dangerously close to your regular speed. So it's very easy to stall the airplane-- it stops flying and starts falling.
Any pilot is trained to recover from a simple stall. In fact all you have to do is put the nose down to gain speed, or in this case drop to a lower altitude where the air is thicker. The plane climbed to 45,000 feet then suddenly dropped to 25,000- looks like a stall and recovery to me.
It is possible they depressurized the airplane at high altitude to try to put out the fire, and then discovered their emergency oxygen masks didn't work. (Multiple failures at once are rare, but when a plane is lost it is often because of several things that went wrong at the worst possible time-- which is one reason such accidents are so rare.) If so everyone on board would probably be unconscious from this point on, and the plane just flying on automatic pilot.
"Personally, I think that is the most likely scenario. While 45,000 feet is above an airliner's usual cruising altitude, 25,000 is below it. I am just guessing here, but I would think an airliner that had stalled and was falling out of the sky from 45,000 should be able to recover before it had fallen that far. But if the pilots had set the autopilot just to keep the plane flying straight and level the autopilot, being dumb, might just keep trying to do that as the plane stays in its stall and keeps falling. This would continue until the mere thicker air at lower altitude allowed the plane to fly out of the stall on its own.
If the pilots weren't incapacitated when the plane went to its highest altitude, the plane stalled, forcing them to lower altitude again. There the fire flared up again, and the pilots were overcome by the smoke.
In any case the pilots were incapacitated, and the plane flew on from there on autopilot, going wherever it happened to be pointed.
It is likely everyone else on board was also incapacitated or dead by the time this happened. We can hope so because if not they were on the wrong side of a heavily armored security door designed to make it impossible for passengers to break into the cockpit-- and they were along for the ride to nowhere with nothing they could do.
Certainly anyone aboard would have tried to use their cell phone, but the range of a cell phone out to sea is three or four miles maybe, and they were hundreds of miles out." -Bill via Amazon Discussions
