The apparent erratic conduct of flight MH370 and the disabling of some communication equipment could be explained either by impaired pilot judgment typical of hypoxia (oxygen starvation) triggered by a slow cabin decompression, or because of the intervention of someone onboard with limited flight piloting experience who may have tried to replace the hypoxia incapacitated crew. The slow decompression could be due to an operational error, as was the case for Helios Flight 522, or because of structural failure.