AF447

[Hyperveloce]

Yes jshg, I have also read that the TO/GA LK could only result from the activation of the alpha prot (the AoA law was only available before the ADR disagree and the deluge of ECAM alerts, it is lost in ALTN2). The thrust index N1 will also be locked if the A/THR fails, then "THR LK" will flash on the FMA at the top of the PFD (the PF should not miss it if he is hand flying the plane ?) when the ECAM will display "AUTO FLT A/THR OFF". Will the FMA diplay THR LK or TOGA LK if the N1 was full thrust (TO/GA) when it was locked ?
If one of the planes (Pitot freezing) found itself in TO/GA LK after the ADR disagree, does it suggest that its alpha prot had activated just before ? If the A/THR was manually set to OFF, it shouldn't have been chasing airspeeds in this case (but wouldn't the alpha prot. also reduce the AoA or the pich ?)
As the AF 447 is the only case with an engaged A/THR when the problems occured, I would really like to know whether there is a mean to confirm that an A/THR in managed speed mode can chase declining airspeeds (thus reducing the margins left to the pilots). But whether it was an alpha prot. activation or an A/THR chasing declining airspeeds, the result would be similar: the automation reducing the margins of the pilots/crew before it threw the towel ? The next question would be to know whether these two possibilities can remain outside the situational awareness of the crew (taking in account the context).
In any case, assuming that the pich was lowered and the thrust was increased either by automation or the crew, I feel it would be really interesting to know if the crew had only 30 sec and 60 sec before the plane reached MMO and Mach 0.9 (for example assuming a 2° descent from FL350 and TOGA). To know how much time left the crew had to recognize/acknowledge the overspeed situation.
(actions: thrust on idle, airbrakes deployed, severe overspeed: lower the landing gear ?)
keeping in mind the possible PRIM1/SEC1 voluntary reset (between 02:13:15 and 02:13:30): if the airbrakes were deployed, they would have been retracted by this event whether it be automatic or manual.
Jeff