Originally Posted by CONF iture
Not my point - What makes phugoid damping a feature of high AoA protection but irrelevant when high AoA protection is activated from pitch command initially ?
In other words, by which subterfuge Bechet is not subject to phugoid damping as he is obviously hitting high AoA protection too ?
"Not my point"? IIRC you made it a point.
Bechet pulls the sidestick abruptly fully back at an AoA where the FCS is in pitch command mode and there is no phugoid damping. Therefore the airplane starts to pitch up achieving a rate of 2.5°/second one second later. About again one second later the AoA exceeds 14.5° and the FCS goes into alpha-protection mode. The elevator then moves to more nose-down positions in a way that is quite similar to the accident sequence and the rate of rotation starts to decrease. However, the inertia of the airplane pitching up at 2.5°/second and the nose-up pitching moment of the thrust increase allow the airplane to continue pitching up to about 16.5° while it begins to climb. That is what I see in that plot, although the resolution of the plot is not sufficient to show the AoA that is achieved.