Originally Posted by ZeeDoktor
@takata: Let's look at what we know.
- The last position received was at 02:10:34. That's 20 seconds after the AP switched off and problems obviously had begun.
- At 02:12:51, ADR disagree triggered, with concurrent loss of AOA protection
- Assuming they had taken evasive action shortly after 02:10:34 by initiating a left turn, they would now (~2.5 minutes later, at 02:12:51) be just about overhead where the wreckage was found and would probably be just about coming out of the left hand course reversal
- Enter a deep stall / flat spin at that point, facilitated by lack of AOA protection, pitch and power flying in turbulent conditions in a turn
- Assuming ~350ft/s descent rate in flat spin, impact with water would have happened ~1m40s later (if still at FL350 when entered)
- time predicted for impact: 02:14:31, that's 6 seconds off from when transmissions ceased. Very close.
My understanding is that the system switched to "Alternate law 2" from the begining at 02.10. Then, "AOA protection" was lost from the start of the sequence anyway.
Why would they initiate such an "evasive action" at 02.10 while they had to keep flying "pitch and thrust"?... this would not be very smart without a real need to do so. During all the similar sequences documented so far (more than 36), not a single crew did take such an initiative to make an "evasive action" only due to unreliable airspeed data.
Nothing is telling us
for sure that the aircraft impacted at the end of the ACARs transmition (02.15). In fact, without engine power, no more ACARs would be sent anyway.