“Conflicts with latest report that one of the transponders was turned off before the pilot’s last sign-off to ground control.”
I thought that report had itself been debunked/retracted. Apparently, the transponder’s last ping was before the pilot’s sign-off, but that transponder only ‘pings’ every 30 minutes.
Close. Yes to “debunked”, but you’ve got flight data system confused with transponder. ACARS pings a database of information every half hour; the Transponder is real-time but communicates very limited who/where data.
Near as I can tell, the time line goes something like this...
1:0? a.m. Computer has been reprogrammed for course change (according to NYT)
1:07 a.m. ACARS “pings” data release, including changed course
1:19 a.m. Everything fine, co-pilot calmly says “Good Night” to Malaysia ATC during handing off
1:20 a.m. Plane begins change of course
1:21 a.m. Transponder goes out, no more comms...
1:22 a.m. Plane disappears from Thai radar
1:28 a.m. Thai military radar picks up unidentified craft (not flying NNE)
1:37 a.m. Expected ACARS 1/2 hour “ping” does not occur, and never does again
2:15 a.m. Malaysian military contact over Pulau Perak
If the NYT report is correct - that the 1:07 ACARS reported an amended flight plan, with the change to be executed at just the moment comms went down, and just moments after signing off with Malaysian ATC - then I do not know how to reconcile this with a random mechanical event.