Originally Posted by
onetrack
Man-made equipment breaks and suffers maladies that combine to cause unplanned destruction, despite the best efforts of thousands of brilliant designers and numerous redundant systems. When that happens, aircraft obey the laws of gravity.
Indeed. The only hard evidence we have to go on, after 3 weeks of analysis, is the brief PSR returns and a small number of satellite handshakes as provided by INMARSAT.
The satellite handshakes are believed to show the aircraft heading south. There are also a small number of handshakes that are not keeping with the hourly keep-alive inquiry. One of those is the partial one (the last communication with the satellite) plus several at the incident time (aka the FIR boundary over the Gulf of Thailand).
Several commenters have wondered aloud about that last partial handshake. One comment (several hundred comments back, concerning the full sim run with fuel starvation) suggested that failed electric was briefly/partially restored when the RAT deployed. This may be connected with the partial handshake at the end of flight.
That leaves us with the several unscheduled handshakes at the incident time. Could it be that those were also due to loss of power, and then a resumption of power to the SATCOM ? If something catastrophic happened to the power bus(es), over the Gulf of Thailand, the pilots may have found themselves with an extraordinary unexpected workload. Several of the failed comms systems have been described as "can only be disabled via the CBs". Too many circuit protection devices tripping simultaneously ?
One possible scenario that does not involve malice on the part of the flight deck crew, nor any of the passengers.