Re Lemurian's instructive post about the likely cockpit scene. quote (emphasis added):
So, we’re left with the necessity of an “UNRELIABLE AIRSPEED INDICATION” check-list, in itself a non-event in most conditions. In this case, they had the speed, they had the thrust..just match the T/Ls with the present N1 and they would have been very close to the needed parameters for level flying at the same speed.
By personal experience, alternate law flying is hardly noticeable : the ailerons feel a bit heavier and slower to respond but that’s about it.
This is a point which I, as a non airbus ex-pilot, find not only interesting but possibly the key to the question often raised in this thread about why AF447 came to grief while others survived a similar emergency.
As I understand it, in all laws other than direct, the basic pitch law remains C*, which means that the stick demands vertical acceleration, and the aircraft exhibits no natural speed stability. So while alternate may well be a no-brainer in smooth conditions, just how easy is it in turbulence? In a conventional aircraft in severe turbulence one is taught not worry about altitude but to gently control attitude within bounds and leave the trim severely alone. But from the A320 onwards, the side stick idoesn't control attitude directly, and the Horizontal Stabiliser is free to do its own thing (unlike conventional controls where if you don't touch it, it stays put).
The thread on LH landing accident at Hamburg last year revealed widespread lack of understanding of the Airbus control laws in roll (specifically what to in a cross wind, with many contributors swearing that it was totally conventional, it isn't), is there a similar lack of knowledge being shown here, in an admittedly much less common situation?
Even if the conditions in which AF447 found itself were not as awful as some have suggested, I can well see how skills appropriate to conventional aircraft may have been inadequate on that night.