@LW_50:
Hullo sir - I do in general agree with what you're saying. If you don't mind a bit of clarification though, the stall warning was not explicitly "disabled" by the logic, it was more a case that the stall warning cannot function without reliably functioning AoA vanes, and the AoA vanes cannot function reliably without at least 60kts forward airspeed. While this scenario is part of the Airbus design spec, there has been a curious level of silence from other builders with regards to whether their current systems run to a similar spec or not. One might suppose that if a better spec existed from another manufacturer, they would have said so by now.
As I recall the discussion from the earlier threads, it quickly became apparent that this particular scenario is rather difficult to solve for every possible permutation of circumstances. The concept of "no warning is preferable to a false warning" is a reasonable one, but it seems that few thought it likely that one could apparently drop below 60kts IAS in mid-air, then come back to it from behind and reactivate the warning.
As for "fighting over the controls" - the only "DUAL INPUT"s happened towards the end of the sequence. As you state and I mentioned earlier, Bonin verbally handed over control to Robert more than once and both times silently took priority back. Robert's priority button would have changed to red in that instance, but in the heat of the moment it wouldn't be a tricky thing to miss.
I ask everyone to have another look at Fig. 64 and see what they think about the following points:
It may be possible that the roll direct aspect of Alt2B might have thrown Bonin initially, but consider these points:
- Bonin had *no* training or experience in high-altitude manual handling in Normal Law, let alone any of the Alternate configurations - how could he have known what to expect (put another way, how could he be 'thrown' or 'confused' by the control law change when he had no prior experience with which to compare it)?
- Take a close look at the "Lateral Wind" graph alongside the pink trace on the "Roll Attitude" graph. At the moment Bonin took manual control, a 25kt right crosswind with an updraft component suddenly dropped sharply. The pink trace indicates that even with no input, the simulated aircraft actually rolls about 2 or 3 degrees to the left from inertia.
- The right crosswind returns and averages around 30kts for the next 12 seconds, but at this point, Bonin's initial overcontrol to the left has him disorientated and making input reversals.
No matter what control law you are in, or even if you're in a type with traditional controls, I'd imagine that kind of initial quick reversal would be very tricky to damp out manually, and practically impossible if you've just been handed control from the AP with little warning. The return of a near-constant right crosswind for the next 12 seconds can only complicate matters further.
Penny for anyone's thoughts?