Hi sensor_validation, bekolblockage, everybody,
A340 AIRPROX;
Originally Posted by sensor_validation
You have to go back more than 43 pages! The ballistic zoom-climb trajectory demonstrated by the A340 was suggested as soon as the proximity of the crash site to LKP confirmed - and the FDR plots in Appendix B of the AAIB report re-published a couple of weeks ago. But the A340 in daylight did not lose air-speeds so flight control laws and protections not the same as AF447 - but was way above safe height and must have been very close to stall at the apogee at FL 384 "where the airspeed had decayed to 205 KIAS and 0.67 Mach even though full thrust had been applied". Full thrust was from protection even though A/T off.
Full thrust was not from protection. The report messed up stuff.
Alpha_floor (as quoted in report) is inhibited above Mach 0.53 if I remember correctly.
Autothrust was disconnected by the crew: they should have received a THRUST LOCK signal (no ALPHA LOCK as reported).
Thrust increased from under 70% N1 (where the autothrust settled it because of the overspeed event before manual disconnection: overspeed protection is first managed by the autothrust) to 100% N1 in a short while. It is unclear if it was due to manual action (I guess it was because N1 was previously stable around 90% before turbulence encounter).
In this case, the climb (and pitch increase) is related to this sharp thrust increase (4 engines at 100% N1), being not countered by nose down imput from the PF.
Autopilot was first disconnected due to overspeed (it was not due to Alpha prot).
This TCAS event just added to the confusion.
Stick pitch axis data on the graph seems also inverted (or alpha_prot kicked at the top of the climb, but it is hard to see it without any AoA data track pictured on the graph - quite disturbing as to suport the AAIB comments).