Originally Posted by
Owain Glyndwr
I think the point being missed in the discussions of 'sensitivity' and 'startle' is that there was a fundamental change in the piloting dynamics when the FCS reverted to direct law. IIRC in normal and Alt laws a sidestick movement commands a roll rate, but in direct law sidestick commands roll acceleration as in most aircraft.
You remember right, however in this case the aircraft did not degrade to Direct Law, but to Alternate 2 (the equivalent of Alternate [no speed stability] on the A320 IIRC). In Alternate 1, roll is still rate-commanded, but in Alternate 2 the roll commands become direct. In Alt 2 the pitch commands are still rate-commanded, unlike Direct Law.
While I agree the dynamics definitely change in Alt 2 versus Normal Law, there are two caveats - namely that there was no immediate need to make significant roll inputs upon AP disconnect (and thus risk potential PIO), and that as the PF had no training in high-altitude manual handling at all it is conceivable that he may still have initially overcontrolled even if the roll aspect was still rate-driven.
EDIT : Though, as pointed out, I am not an aviation professional, I do however submit that this should at least be considered a matter of common sense - namely that if a malfunction (which will initially be of an unknown nature) has occurred, then it would be advisable to treat the flight controls very gingerly at first, because you don't know what works and what doesn't. I believe the phrase used in the mega-thread to describe the inputs made by the PF was "stirring the mayonnaise" - and this is something to be avoided absolutely unless there's an obvious and life-threatening reason to do so.
Indeed, most of the incidents and accidents I can think of in which the outcome was at least relatively successful have involved the crews concerned doing just that - "feeling out" the aircraft to see how it responds, what works and what doesn't. Examples include UA232, QF72, BA009 and NWA85 - not to mention the other 30-odd incidents of Thales AA-related UAS problems!