A33Zab:
In respect of Capt, IMO he realized exact what was going on!
After entering cockpit ordered or pulled T/L into IDLE and ordered ND inputs! see
LINK
I don't see it quite as definitively, but I suspect you may be right on the TL's to idle. If the ND inputs were ordered I'm surprised (but only a bit) that the BEA didn't include the CVR for that exchange - in my opinion that would be quite significant.
BEA:
At around 2 h 11 min 40, the Captain re-entered the cockpit. During the following seconds, all of the recorded speeds became invalid and the stall warning stopped.
The altitude was then about 35,000 ft, the angle of attack exceeded 40 degrees and the vertical speed was about -10,000 ft/min. The airplane’s pitch attitude did not exceed 15 degrees and the engines’ N1’s were close to 100%. The airplane was subject to roll oscillations that sometimes reached 40 degrees. The PF made an input on the sidestick to the left and nose-up stops, which lasted about 30 seconds.
At 2 h 12 min 02, the PF said "I don’t have any more indications", and the PNF said "we have no valid indications". At that moment, the thrust levers were in the IDLE detent and the engines’ N1’s were at 55%. Around fifteen seconds later, the PF made pitch-down inputs. In the following moments, the angle of attack decreased, the speeds became valid again and the stall warning sounded again.
At 2 h 13 min 32, the PF said "we’re going to arrive at level one hundred". About fifteen seconds later, simultaneous inputs by both pilots on the sidesticks were recorded and the PF said "go ahead you have the controls".
Immediately following the Pilot's arrival, we have 30 seconds of sustained NU though.
