Intentional =/= terrorist hijacking/pilot suicide/random heist theory. A pilot trying to save an aircraft does things intentionally.
It would take an even more bizarre set of circumstances than hijacking to explain the behavior of the plane as we know it so far.
Transponders: disabled to deal with fire or as a result.
Closest possible airport: the one the plane turned towards was arguably the best one to go for.
Radio silence: disabled by fire.
Fr. Occam is pacing back and forth and stroking his beard on this one, that's for sure.
Or they could apparently have taken a second to activate the 777's Emergency Locator Transponder, powered by its own battery and with its own hardwired, non-computerised switch circuit to the cockpit.
You could imagine the aircraft accidentally flying (and transmitting over SATCOM) for hours with no other communications if there was some kind of crisis that completely cut off the pilots' (and passengers') ability to use the flight controls for the whole time (quite possibly by killing them) without damaging plane's systems much overall. Hypoxia or smoke inhalation seem plausible. Some kind of fire that completely destroyed the instrument panel without spreading too much further sounds vaguely possible. (IIRC at least one of the pilots had a habit of smoking while flying.) Surely both pilots couldn't somehow have locked themselves out of the cockpit behind the security door? The problem is that such a scenario is hard to square with a flight path that apparently included multiple changes of course and altitude long after any initial cockpit emergency https://news.ycombinator.com/item?id=7420894 .
That does raise the question of how many turns there really were, though. Earlier reports based on radar suggest that the plane made several course changes as it flew in a zig-zag around the Malacca Strait and Andaman Sea west of Malaysia. If enough of those apparent sightings can be knocked down then an accident becomes more likely. Though even one change of direction onto one of the final SATCOM arcs, apparently without any effort to communicate at the same time, is a real head-scratcher if you assume no foul play at any stage.
There was a theory posted here earlier that it was a fire that initially took out the transponder and possibly comms.
The fact that the plane has not been found is very strong evidence that it did not crash. If it crashed on water, some debris would most likely have been found by now. If it had crashed on land, someone would have noticed the resulting fire.
The in-flight fire theory is not plausible because the 777 is fly-by-wire. A fire severe enough to knock out the comms would almost certainly have taken out the fly-by-wire system as well.
And no, cell phones don't work at 30k over water, but they do work at 10k over land. Like I said above, the fact that no wreckage has been found is very strong evidence that the plane landed intact. At some point during that process the plane would have almost certainly come into range of a cell phone tower somewhere.
Isn't that what the oxygen masks are for?
False, nothing here is inconsistent with a mechanical problem. When the NTSB/FAA come out and say they've ruled out mechanical problems let me know.
> The fact that the plane has not been found is very strong evidence that it did not crash.
Almost everyone believes it has crashed. When the NTSB/FAA say otherwise let me know.
> A fire severe enough to knock out the comms would almost certainly have taken out the fly-by-wire system as well.
This seems like random speculation. Some of those systems would turned off by the flight crew intentionally as they go down a checklist.
The total lack of communication combined with hours of continued flight with course changes is inconsistent with any plausible failure mechanism. I have seen no plausible theory of a mechanical failure that can account for these facts.
> Almost everyone believes it has crashed.
So? This would not be the first time that almost everyone was wrong.
> This seems like random speculation
It is certainly speculation, but it's not random. I'm a pilot with a degree in electrical engineering.
> When the NTSB/FAA say otherwise
"We cannot rule out X" and "it is probably not X" are not mutually exclusive statements. (And, BTW, an inside-job hijacking and a crash are also not mutually exclusive.)
We cannot rule out anything until we know for certain what did happen. But that does not prevent us from drawing tentative conclusions what is and is not likely based on what we do know.
>The fact that the plane has not been found is very strong evidence that it did not crash. If it crashed on water, some debris would most likely have been found by now.
The current "most likely water crash" area has only started being searched today.