pings. whatever took off the transponder was mechanical and could have also damaged control center, which monitors climate. >> in the case of decompression, happens quickly. a minute or so. in the case of smoke, pilots have a greater oxygen supply than passengers do, so they could have remained active for longer. all this could have taken no more than 10 minutes at the most prf skeptics say the som biscenario is highly unlikely because of the behavior of the plane and crew. >> changing altitude, coming down to land safely. changing direction and changing heading. and professionally and by training you would let somebody know, air traffic control. so an emergency signal would have been broadcast. it may they tried to send a signal and for some technical