Originally Posted by
maDJam
At a height of 900 m there was a simultaneous control column nose down input and stabilizer nose down deflection from -2,5 deg (6,5 units) to +2,5 deg (1,5 units) (the FDR recorded a nose down stabilizer input from the stabilizer trim switch of the control wheel lasting 12 seconds, while the CVR record contains a specific noise of rotation of the trim wheels located on both sides of the central pedestal), as a result the aircraft, having climbed to about 1000 m, turned into descent with negative vertical acceleration of -1g.
I still think the answer lies in that quote.
If they pushed -1g to gain the level-off altitude, and neither were familiar or comfortable with the sensations of negative g, they may well have done something unpredictable. As I said before, I have seen students either freeze and keep pushing, or think they are stalling and keep pushing. And since aeros are not a part of ATPL training, this crew may not have been familiar with negative g at all.
As I have said many times on these forums, at some point in the training, perhaps at upgrade to sfo, all pilots should do a two-week gliding course. Gliding is unique, in that it is all seat of the pants hand flying, in the most challenging conditions. In a strong bouncy thermal you might incipient stall the glider ten times while banking at 45 degrees - it is normal, and the reaction becomes normal. Positive and negative g are a central part of bouncy thermal flying. And of course all the training aircraft are certified for full aerobatics. If you are a (young) commercial pilot who has never flown a glider, I can assure you that you will come out of the course having learned many things about aircraft about aviation, and more importantly, about yourself.
ST.
(note typo error correction - changed 'pulled' to 'pushed')