Clandestino, Ruderrat,
An interpretation that the pilot has intentionally, in full knowledge of the situation entered NU commands, calls for a reminder of the confusion shown by the CVR transcript in the BEA report.
Furthermore, there is additional data to consider - such interpretations were advanced before on the AF 447 threads, but do not recall them being documented this way.
The combining of the Pitch and Roll control BEA graphs - see bellow - show a significant coincidence and persistence of Pitch and Roll commands.
As I think it is normal that not every Pitch command required a Roll, and vice-versa, this can be interpreted as:
a). a lesser familiarity with the separation of the two types of commands on the stick, and furthermore:
b) a lesser familiarity with the Neutral position of the stick.
Consequently, it seems that what would have been a perceived Neutral position of the stick for Pitch and for Roll commands, was in reality a OFF Neutral position, in reality a NU command, and respectively a Roll command.
In conclusion, this can be interpreted that the persistent NU commands were not intentional, but just a simple consequence of the handling of the stick.
If the NU commands were not intentional, than the Autotrim of the THS to max NU was not intentional.
Furthermore, the THS was positioned to the max NU position during the Stall Warning time interval, contrary to what the computer logic would have asked for, if the two logical paths (Stall, and Autotrim) were linked.
Note: if we expect the pilot to conclude that in STALL a NU commands is a NO, NO, why shouldn't we expect the computer to arrive at the same conclusion???
It is possible that the BEA work on the Human Factors and a future report will add more analytical elements, interpretations, conclusions, and recommendations that may intersect with elements presented in this post
Originally Posted by
Clandestino
Well, duh. It is supposed to be that way. I don't mind writing for a zilionth time that DP Davies has it all neatly explained.
Just when did he relax the backpressure? You are acquainted with sidestick traces from 3rd intermediate report, aren't you? A couple of times stick goes forward but quickly gets behind neutral again and stays there before elevators even have the chance to get to neutral.