“Or all three.”
Or, a fourth; I’m guessing that whatever happened the pilots or a pilots was involved. One pilot killed the other or perhaps both pilots nosed the plane over and flew it into the sea. However, I doubt this scenario because there’s no debris to be found. Or, one or both pilots switched off all sending/tracking systems and flew the plane at low altitude to a remote airfield where it is being hidden to be used in a terrorist attack in the future. Passengers have been executed. I don’t buy the mid-air explosion theory as there would have been debris on the water. Impossible to ionize a complete 777 so that there are absolutely no pieces left to be found. Anyway, at the moment, my theories are as good as anyone else’s :)
To
I believe there have been firmware updates to nav/com systems that cause some data to be transmitted even when the gear is switched off. Actually, like cellphones, some of the gear has no actual off setting...the processors just go into sleep mode but still are on....and watching for events. Even physically disconnecting the power leads to some gear won't shut them down as there are internal batteries that keep the processors alive for a time.