Originally Posted by HN39
Once Alpha-prot is engaged, it remains active until a nose-down command is given with the sidestick (see the FCOM and the AAIB Bulletin). Until that occurs, "the AoA protection law seeks to hold the angle of attack constant at alpha prot".
That was true at the time, but things have been slightly (and discretely) modified since, maybe partly due to that event.
The text in the FCOM is a bit ambiguous but says that it is now also possible to leave the AoA protection if the sidestick is
at neutral or pushed forward, for at least 0.5 seconds, when alpha is below alpha prot.
Nothing is that simple with the airbus, a
very complex machine indeed.
We'll be told (or not ... ) if some bizarre coincidences mixing unreliable airspeed indication + protections played a trick on AF447 ...