One "fact" that has not been mentioned much here is the (supposed) radio contact between MH 370 and another aircraft in which an MH 370 pilot (likely the FO) was reported to be "mumbling".
As reported (and the source seems to be
MISSING MH370: Pilot: I established contact with plane - General - New Straits Times on 9 March):
- the pilot was ahead of MH370
- they were asked by Vietnamese flight control to contact MH 370 just after 1.30am to ask its position, as the Vietnamese could not locate the aircraft
- they did so and established contact: "We managed to establish contact with MH370 just after 1.30am and asked them if they have transferred into Vietnamese airspace."
- but: "There were a lot of interference ... static ... but I heard mumbling from the other end. That was the last time we heard from them, as we lost the connection."
- "The voice on the other side could have been either Captain Zaharie (Ahmad Shah, 53,) or Fariq (Abdul Hamid, 27), but I was sure it was the copilot"
- "Following the silence, a repeat request was made by the Vietnamese authorities to try establishing contact with them."
Based on the timing, the reported destination (NRT), the statement that the aircraft was a 777 and was "far into Vietnamese airspace when he was asked to relay" and the fact that the pilot knew enough to recognise the voices on MH 370, the relevant flight would appear to be MAS 88, KUL-NRT, a 772, scheduled dep 23:35, which was near Da Nang at that time.
**If** this indeed occurred, it seems to me to be pretty important in working out causation as it would show:
- there was something wrong enough to cause incoherence and, it seems likely, no further subsequent contact;
- radio working, with Fariq speaking; but
- crucially: there is no attempt by MH 370 to hide itself (e.g. by simply not answering) and indeed there is action inconsistent with an attempt at stealth
The latter would be hard to reconcile with a rogue flight deck or intruder bent on stealth, unless it is the aftermath of a scenario similar to FedEx 705 with either: a rogue left able to fly stealthily and who does so, or no-one left able to continue flying.
So it would seem to be a major factor in pruning the probability tree to either (1) an accident with incomplete recovery due to incapacitation or (2) an intentional incident on the flight deck that left Fariq able to make that contact but then (a) left no-one able to aviate or (b) left someone aviate who was unable to or chose not to make contact.
So: what is the source and status of this "fact"? I haven't been able to find anything "official" (for what that's worth), but it seems unlikely that the NST would print something like that if it were complete fiction.