Re: F-GLZU
FWIW, the way I read the traces shows....
Except for the initial pilot commanded pitch up (FO SS ANU -11) in the first period of alpha prot activation (and maybe the reason for it?), every subsequent entry into alpha prot shows an initial pitch attitude decrease as Mach decays, particularly pronounced at the lowest Mach numbers which is what I would expect.
True, there are minor <1 or so degree pitch variations after those initial pitch downs that I would think could be attributable to 'rough air' and FCS lag. Pitch trend is down or stable.
There are 3 or 4 very minor pitch oscillations (time scale proportioned) in that final long period of apha prot, but in general, with the trim frozen ('prot' occurred at around minimum Mach) in alpha prot, pitch does not trend an increase until calculated Mach number tends to increase continuously from a low of around 0.68 and I would assume there would be a noticeable CAS increase and associated frozen trim pitch up effect to maintain trim speed with this, especially since altitude is still generally decreasing further increasing CAS for the Mach. Possibly even FCS 'AND' elevator commands during this pitch increase. Elevator trace would be nice.
However with the apparent errors (pedantic or not) in the 2 AAIBs, i.e. 'probably alpha floor' with the minimum Mach of 0.67 in the Airprox event and the reference to an 'amber AP OFF' message in this event, I'm beginning to lose my warm fuzzy about the learning value of some of these reports.