latest Is it carried on flying for a few hours with its comms deliberately turned off, in opposite direction to intended. Maybe it was in the hold of an alien mother ship....or a hijacking attempt went wrong , ie maybe the crew tried to overpower hijackers, it went tits up and plane then crashed.
Rivetting though aint it !
I did think aliens straight away though...anyone who is up to speed with " ancient aliens" must know its time they came back....this could be a good showpiece return........nick a plane, then a week later let it go back in the sky ...that wud be a story and a half.