It should also be noted we have a max deviance of 20 degrees on the AOA data from the FDR, which means the aircraft would pitch down a maximum of 18.5 degree roughly (assuming 1.5 degrees is normal AOA)
That means the rapid loss of altitude in the logs cannot be solely attributed to the auto trim and your 6-second number becomes something more on the order of 30 seconds, which IS more than enough to grab the yoke and do something.
I will sugest that you make your self aware of the difference between AoA and pitch so you dont spread misinformation.
In steady flight one sensor can correctly read 2 degrees AoA and the other a erouneously 20 degrees.. The plane pitches down reaching a steady 20 degree pitch down attitude. The working sensor will still read about 2 degrees AoA and the faulty one will still read about 20 degrees AoA.
Explain to me how the aoa wouldn't change exactly when constantly pitching down. Maybe I am missing something but if pitch is constantly being lowered aoa should continue to change as the relative motion should be changing constantly. There may be some equalibrium point but if the pitch down is constant shouldn't the aoa continue to change until to motion vector stabilizes? Maybe I am missing something it is late so happy to be corrected.
The AOA tells you something about how much lift the wing is generating. At zero degres AOA the wing is generating zero lift. At steady flight in normal speeds you might have 2 degrees AOA as you correctly suggest in another post. The wing is then generating the same lift as the weight of the aircraft and the aircraft flies happily away at constant altitude and 1 G.
Now, assume that one AOA sensor is way off and in this example is indicating an AOA which is 20 degrees to high, that is one sensor indicates the correct 2 degres and the other one an incorrect 22 degres.
Then we pitch down the aircraft to a 10 degrees pitch down attitude. We wait until the aircraft is stabilized at this attitude. The aircraft is now flying along a line pitching down 10 degrees and the aircrafts altitude is decreasing with a constant number of feet per minute. But the G experienced by the aircraft and its passengers and crew is still 1 G, since the aircraft is following a straight line with no vertical acceleration. Therefore the true AOA must still be the same ca 2 degrees as previously since the wings still need to generate the same lift as the weight of the aircraft, which has not changed. So, the correct working AOA sensor is still indicating ca 2 degrees AOA, the faulty sensor is still indicating 20 degrees to high AOA, that is it is still indicating ca 22 degrees AOA.
Lets say we pitch down the aircraft to an insane 90 degrees pitch down attitude and stabilize the aircraft. Now the wing dont need to generate any lift since we are flying straight down. The true AOA is therefore zero degrees.. The correct AOA sensor is indicating zero degree, the faulty one 20 degrees more, that is the faulty sensor will now indicate 20 degrees AOA.
So, we see that as the aircraft pitches down the true AOA gradually decreases to zero degrees as long as a particular attitude is stabilized. Any AOA sensor with a constant positive error will therefore never reach a value of zero degrees in any constant pitch attitude between level flight and 90 degrees straight down.
I can add that this explanation is valid as long as the roll rate is zero or at least very low.
Edit: I have omitted some details, like a possibly angular deviation between the wing chord line and and the fuselage senterline and some other minor details. So if someone was going to be very pedantic (s)he could find some minor errors in my explanation, but the principle still holds true.