it would explain why there may not have been communication. >> are there any suspects? >> they've gone through everybody on the aircraft and determined that there is no one there that would match the profile of someone who would take over that aircraft. >> if not human intervention, could something on the plane have malfunctioned? >> it's got to fly for another six hours. that's the problem. the mechanical questions. >> what kind of catastrophe could shut down the plane's communications, but still have allowed it to fly? >> anybody that chooses to hang their hat on one scenario or the other, in my view, is heading for a fault. the entire experience of air crash investigations is that, yes, it's usually the obvious, but it's quite frequently, it's something you'd never even thought of. >> there's no way to know, until