Chris
I think your assumption of post phase advance needs to be modified. Let's say Valpha prot is 5 degrees (in cruise) and rapid increase in angle of attack causes protection mode to engage at 3 degrees but the rapid pitch up will take it past 5 degrees and when the gust has passed it will pitch down to 5 degrees. Where is the problem? If pitch up was gradual there won't be any phase advance and it would have engaged at 5 degrees and it will resist any more pitch up if possible or will come down to alpha prot when possible. Valpha Max gets adjusted and it is successfull maintained even in windshear. You cannot compare 447 because it was in alternate2. There is another likely misunderstanding about change in AOA mode to Load factor mode. From FCOM below
Thesystem will regain the normal load factor law if the stick is pushed forward ofneutral, but it will re-enter alpha protection if the stick is released with the angle of attack still greater than the value set for alpha protection. Thus to exit alpha protection properly, the pilot should reduce angle attack to a value less than the value set for alpha protection.
These are only mode changes and not pitch ups.
Last edited by vilas; 9th Nov 2013 at 18:33.