Here's two facts.
The Satellite Data Unit (SDU) stopped working and then started working again.
The track taken from the tip of Sumatra to the most likely search area was a straight line. If you measure the known distance of the flight prior to the turn south, and measure a straight line to the search area from the turn south to the search area, you ind the aircraft had fuel to accomplish that track, and no more.
So, why would the SDU go off and come back on again, and how do you accomplish flying a straight line in a Boeing without some input from someone who knows what they are doing?