@henra
Thanks very much for your explanation.
In one of the early posts on this thread, the flightaware, or other source, showed a heading of 024 degrees. The next heading, in the same minute showed a heading of about 340 degrees (if I remember correctly). That was the last data transmission.
Some "reliable sources" had said that radar data shows the plane turning back.
I wonder if this could have been the start of a high speed problem from which there was no recovery.
Regards,
OBD