high incidence
Hi there,
The BEA note states that
- most of the pilot actions were pich up commands
- @ 02:10:51: incidence around 6° (when the stall alarms sounded), TOGA, pich up commands. 15 sec later, incidence around 16°, FL380, pich up commands again
- @ 02:11:40: end of stall alarms, FL350, -10 000 fpm, pich angle 15°, N1=100%, large (40°) roll excursions, pilot commands: roll compensation & pich up (during 30 s)
- @ 02:12:02: FP says "no longer any reliable indications", N1=55 %, 15 s later: pich down commands, incidence is decreasing, IAS reliable again, stall alarms
- @ 02:13:32: FP says "we are going to get under the FL100"
the incidence has always exceeded 35°, and seen from the pilots, the altitude was decreasing rapidly (a bit more than -10 000 fpm) with an inertial piching attitude reaching 15°: how can we explain that most of the pilot commands were to pich up the plane except around 02:12:17 (15 s after 02:12:02) ? Did the crew apply the AF SOP in the early phase (around 02:10:51) by setting TOGA thrust and a pich up at high altitude ? It is only 1 min 11 sec after that THR is on IDLE, the N1 is on 55 %, and that pich down commands are applied.
the stall is not recovered and the terminal vertical velocity is around -10 000 fpm.
why a crew would respond to the early stall alarms by a nose up ? spatial disorientation ? confusion/stress due to multiple conflicting indicators ? or tricky/misliding/lengthy procedures ?
Last edited by Hyperveloce; 27th May 2011 at 15:21.
Reason: correction