Thoughts on the initial climb and later, the implications of deep stall.
- Alt 2 is a roll direct law. This means that the pilot flying will have to control bank angle. Only the aircraft's natural stability will tend to level the wings. Any turbulence will impart a bank angle until corrected.
- If PF had to fly the wings to keep them level, could he have inadvertently pulled the stick back while making corrections, either through nervous tension or bad personal geometry?
- And could his instrument scan have been so rusty that he didn't realize he was inducing a climb?
- Was there anything unusual about the copilots' stature, or technique in gripping the stick? (Realizing we ourselves don't really know who was PF but some guesses can be made).
- Although ACARS does not specifically state that the aircraft later switched into Direct Law, and BEA has not told us (yet), It appears that after a significant period of deep stall, the AOA and A/S on all 3 ADRs had to have been considered unreliable by the system. How can even one Prim stay operational in this situation? If all 3 Prims are not available, the aircraft must be in Direct Law. That would explain the pitch trim staying at 13 degrees after the aircraft actually achieved a deep stall.