Originally Posted by
Mesabah
All those scenarios of stealing/hacking an aircraft, would be too complex to pull off without massive coordination. It's likely the simple answer, fire/smoke in the cockpit crippled the aircraft, knocked out the equipment, and the plane flew to a crash site that is perhaps a thousand miles away. It may be the case that this aircraft is never found.
(I'm no avionics/airman expert by any means so please educate me since this is more of a question), If the aircraft had altered course and crossed over land, wouldn't a country's radar have picked up the aircraft and had fighters/local craft investigate it if the craft didn't respond/wasn't scheduled to be flying there?