Originally Posted by
Machinbird
In the right hands and without all the "protections," your genteel A320 could be made to do a low g airshow on the order of what Bob Hoover did with his Aero Commander.
That's as may be - however not every pilot is on the order of a Bob Hoover, Roly Beamont or "Tex" Johnson. In this case we're talking about an AF line pilot - technically capable, certainly - but nowhere near on the order of a Bob Hoover.
To make it fly in the genteel mode, they have provided some safety margin from the performance boundaries.
The A320 is not particularly "genteel", particularly in airliner terms!
What people are not talking about is how big the safety margins are (that is closely held data because in the wrong legal hands, it could be said that AI took away a pilot's maneuvering margins and thus caused an accident.
That's a rather cynical way of thinking about it
But I'll bet that there was .02 g available from the airframe that the computers were not letting the pilot obtain in the Habsheim accident.
Popping back to HN39's graph near the beginning of the thread:
Originally Posted by
HazelNuts39
AlphaCmd in the graph represents the sidestick position PROFON_CAP, assuming a linear relation between AlphaProt=14.5 for SS=0 and AlphaMax=17.5 for SS=-16.
I've got to say I'm not entirely convinced. Admittedly I'm unversed in the knowledge you're using to come to that conclusion, particularly with regard to CoG height and relationship to lift...
Surely you must recognize the need for some safety margin from an engineering standpoint. There is variability between aircraft after all. Surface contamination of the wings does happen.
Of course - however the margins are not particularly restrictive, again, especially for an airliner. Ultimately, though, the reason the aircraft crashed has nothing to do with the technology. Human factors aside, the overarching reason the aircraft crashed was because where it was going, there was a forest in the way.
EDIT - re:would/should, I think the wording is reasonable as it stands - the crew were briefed to have Alpha Floor disabled in order to perform the manoeuvre, and while the approach was improvised and the Captain's physical SA seems to have been compromised by that, he seemed to be pretty sure that A.Floor was out of the equation.