Originally Posted by Sydy
We have to wait fo the premiliminary report to figure what happened. At least to have an hint about.
Yes, to know with some surety as to what happened. Any idea how long that might be? Are the recorders available? Why wait?
Consider this possibility:
Aircraft in level flight in A/P encounters a serous problem (eg Very Large Hail/ Fire in cockpit/ Depressurization).
Throttles pulled to idle and possibly the nose is dropped.
Crew becomes disabled
(Flight control system is C*, isn't it?) (Also works if C*U)
Aircraft slows.
AOA protection limits maximum AOA and aircraft commences a minimum safe speed descent on previous heading. (If C*U, it would be a phugoid descent)
Does this scenario permit the observed arrival conditions?
Can it match the ATC observed ROD?
If a viable scenario, then that might explain how engines could be at low power but still running (if true).