Salute!
I wish to make it clear that I do not believe the plane was in a deep stall all the way down from cruise altitude. I do believe it was in a stall or deep stall at impact.
- Proximity to impact position from last known seems reasonable for a deep stall all the way down, but impact heading seems to show an intentional or unintentional turn from course. The plane may have even been in a spin for a turn or two or experienced a no-kidding "wahoo!!!" after encountering severe turbulence. Serious problems with the air data sensors is another explanation for an unusual attitude/flight condition due to all the "laws" this plane has.
- The impact damage and wreckage pattern indicate that the aircraft hit the water with a higher vertical velocity than horizontal velocity, such as the French interim reports claim. So a 60 or even 70 degree angle seems possible. Only other reason I can imagine than a stall is that the crew regained control and couldn't quite make the recovery in time. However, with the standard aft c.g. the plane flies with, the stall seems more likely,
- There is also a possibility that it was not sensor problems as much as an extreme aft c.g. that caused loss of control after the plane experienced only a moderate amount of turbulence. Any warnings or displays in the cockpit for c.g.???
On a personal note, the FBW system I flew acted like the Airbus for forward stick with respect to AoA protection.. We only had a positive AoA limit with gear up and that was 25 degrees ( no "protect" mode/value, just max AoA). Our system also had "standby gains" if the air data sensors were deemed unreliable. So two values for total pressure - one for gear up and one with gear down. This didn't limit gee or AoA, but limited the rate and amount of deflection of the control surfaces.
later,
Gums sends...