deadheader said
If you really must persist with mechanical/tech incidents/scenarios occurring at precisely the moment of ATC handover & during what is statistically the safest phase of flight, against the direction of the professional investigation it must be said, then you first have to reconcile one of the few knowns:
A left turn was entered into the FMS & reported by ACARS before comms went offline & before someone in the cockpit communicated with ATC for the last time [without alerting ATC of any unfolding drama].
I would add; two even more reliable knowns, that are extremely important and near impossible to reconcile, need to be addressed in such a scenario
- ACARS never sent emergency transmissions indicating a system failure anywhere on board
- Flight continues for hours, meaning whatever the 'catastrophic event that took out all the systems' was, it seemingly did not effect auto-pilot at all