Originally Posted by
HazelNuts39
...
I am slightly disappointed by Appendix B. The timescale is unreadable and, while the story is about Mach and AoA, there is no trace of either. There is a trace of a 'MMO Exced.' discrete, and I suspect the DFDR also contains discretes for alpha-prot and High Speed protection, which are not shown.
If you compare the 'Pitch' trace and 'MMO Exced.', the High Speed protection may have been triggered briefly, but the pitch trace really takes off after the Mmo exceedances at 14:21:50 hrs, ten seconds after AP disengage.
Regards,
HN39
I think we can safely assume the grid marks are 60,10,5 seconds. - check the RA lasted 27 seconds, and max rate of climb 6000ft/min.
The elevator action presumably triggering the pitch response clearly takes place only a few seconds after AP disconnect, and before AT off, apparently coincident with the second MMO exceed event.
I am intrigued by the comment re alpha-floor - responsible for the N1 max while AT off?
The altitude seems very heavily filtered/ phase delayed - maybe to do with fact that it is "Pressure Altitude"?