US officials and others say the flight experienced significant changes in altitude after losing contact with ground control, and altered its course more than once, demonstrating that it was under the command of a pilot and not merely flying on autopilot. The flight climbed as high as 45,000 feet, well above the approved altitude limit for a Boeing 777, and dropped to 23,000 feet, below normal cruising levels, as it approached the heavily populated island of Penang. It also made at least two course changes, one towards the southwest and another to the northwest, taking it out over the ocean. The data is incomplete and hard to interpret, officials say. Some officials wonder why the Malaysian military did not respond to the flight; Malaysian government officials say the flight was detected by military radar, but the military chose not to respond because the flight showed no hostile intent. A senior aircraft industry executive says,
Everything we have heard is consistent with the plane flying under the control of someone with at least some flying experience.
An Asian Boeing pilot, who declined to be identified, says the ascent to 45,000 feet might have been combined with the depressurization of the cabin in order to render passengers and crew members unconscious, and could have been the act of a hijacker. However, others say that such altitude changes may have occurred because of a sudden disengagement of the autopilot.