So according to Bechet the airplane has no issue going to alpha max
Sorry, I should perhaps have written "phugoid motion at
approximately alphamax". The phugoid damping terms will reduce the AoA slightly below alphamax when the airplane is decelerating, and increase AoA when the airplane is accelerating, as
conceptually illustrated in the chart below.
... but then, what do you make of the Airbus statement that "the flight protection system operated perfectly and prevented the aircraft from crashing nose first" ?
Well, the flight protection system certainly 'prevented the aircraft from crashing nose first'. As to 'operating perfectly' the BEA report notes:
1.16.1.4.2. Réponse de l'avion à une sollicitation à la profondeur à très basse vitesse
La difficulté à reproduire une manœuvre provient du fait qu'il faut se placer dans des conditions identiques ou très voisines de lois de pilotage impliquant le respect de tous les paramètres influents (facteur de charge ou assiette, incidence, gradient de vitesse, positions de manche en profondeur) alors que ces paramètres ne sont enregistré qu'à une cadence faible sur le DFDR (un point par seconde en général) et qu'une restitution exacte nécessiterait de l'ordre de 40 points par seconde.
In short, the recorded parameters are too few and too coarse to permit a reconstruction of the operation of the flight control system in a complex situation with variations of windspeed and angle of attack encountered by the airplane as it flew below treetop height in the wake of the forest.
Also not too sure how you get Valphamax at 113kt ... ?
I stand corrected: Valphamax should have been the Vs1g of 110 kt.
