AF 447 Thread No. 12

[_Phoenix_]

DozyWannabe, interesting suppositions about the back pressure reasons

However, I would not stick with only one possibility

1. initial climb was deliberate, as stated in CVR, his intention was to climb over the weather, but in the same time he had difficulties in controlling the roll, he over-controlled, because of surprise effect and direct law for roll, at high speed. The travel of sidestick in roll is larger compared to pitch direction, therefore by applying large movements on lateral he might applied more back pressure than intended

2. He followed the FD. At 2:10:50, stall alarm goes off, but aircraft was still in climb for next 20 seconds, Bonin pitch command looks erratically, mostly NU input, but if graph is correlated with FD order, it seems he was actually chasing the horizontal line (Final report, figure 28 correlated with figure 69)

3. Inadvertent pull, at 2:11:30 roll command is at max left, but the aircraft continued to roll towards right. He was fighting with roll control, for next 10 seconds, slowly and inadvertently, the sidestick moved from 9 o'clock position to 7 o'clock (dead stop for both roll&pitch)
Bonin might lost the reference of sidestick fwd-aft and left-right. He exits from 7 o'clock corner directly in the opposite corner full right-ND, the opposite combined stop. Then he might re-position his hand, but already was too late... the irreparable damage for THS position was done.

4. overspeed fear - I would just add the aerodynamic noise combined with misleading stall alarm, Bonin might believed that stall warning comes on because the airflow is disrupted when aircraft is approaching the sound barrier