The report said data automatically downloaded and sent to the ground from the Boeing 777’s engines indicated the plane remained in the air for a total of five hours – a further four hours after contact was lost.
but how could it fly on for a futher 4 hours without some sort of radar trace, if only as a large lump of metal i.e. without transponder, and if not following the original flight plan route what were various ATC jurisidictions doing, they must have noticed an unplanned intruder ?