Leightman 957
3. Total (electrical) power loss would have created the known fact of Transponder and ACARS loss.
Except for the continued operation of the Satcom system. Someone will have to propose an electrical system failure that takes the transponder and ACARS down but leaves Satcom up.
And then there's the 'Goodnight' message after the transponder shut down. I understand the need to aviate first. But if you've got the time to key the mic and say goodnight, a little aside to note the ongoing systems failures wouldn't be out of line. Its possible that the ACARS/transponder losses may have presented as passive failures at the outset. But here again, some serious systems analysis is in order to identify the sorts of failures possible. VHF comm was still up at this point, adding another constraint to the problem.