suggested key events
I think that this pulls together some of the
previous suggestions.
Given the decision to do the alpha floor test when they did:
- AoA sensors stuck so alpha prot fails
- stall warning
- throttles forward
- control law to direct : failure or automatically or
manually so horiz. stab (THS) trim stuck full up
- fail to consider (THS) which is full nose up
- rest just follows
- mush mush mush
- nose drops eventually
- insufficient alt to recover within load limit (2/2.5g)
[all the while various wings are dropping and
being recovered]
Clearly the computers are doing some yet to be explained
things but there seems a possibility that above points
are the substantial explanation for the aircraft behaviour.
So we need three slices of cheese
- Poor decisionmaking regarding the test conditions
- AoA probes faulty in some way
- THS trim, rarely used manually,
was required to be operated in this case
if recovery was to be effected.
It appears that the flight controls were functioning
reasonably, except for perhaps the THS trim after stall
warning. What the design behaviour of the THS trim
is and whether that design is appropriate
or whether it performed to that design
is way beyond my capacity to consider.