Originally Posted by roulishollandais
The final loss of height is not your 22000 FT, nor FL200, nor 15000 FT,
but 5000 (max) +(FL100-FL76)=7400 FT
Dutchroll, these were speculative numbers for a last minute escape from the full stall. The pullout is dependent on achieving near maximum performance, and the stall recovery altitude/time is entirely speculative. The emphasis should be on
speculative. Remember, this is for near maximum performance. Without an AOA indicator, I see no way to come close to these numbers. OK465 seems to believe it will be a problem teaching people when and if to add some power during pullout to improve performance. He is probably correct.
My intent in coming up with these speculative pullout figures is to remind people who may be in similar situations to not give up! You might think you are toast, but keep thinking and keep flying to the limits of your ability. You just might get a pleasant reward. The light at the end of the tunnel is not always a train.
PJ2s post #1107 (
http://www.pprune.org/7109943-post1107.html) is the result of a number of simulator runs of the AF447 scenario and involved a
high altitude initiation of the recovery. This is essentially valid data within the unknowns of how well the Sim matches reality in an area it isn't really certified for. Perhaps PJ2 can tell us something about the power setting during the recovery. (High power would be a worse recovery condition than idle power.)
If the recovery is initiated lower, it is likely that the pitch rates nose down will be higher, the descent rates a little lower, and thus the time/altitude loss to unstall the wing may be somewhat less.
Just like the Viper has a sticky spot in its pitching moment curve, the A330 may also have a sticky spot. There may be techniques for achieving a higher nose down pitch rate, but it is not worth risking a test crew to find them. With proper fixing of the myriad Swiss cheese holes that led to AF447, we should never see a similar incident involving an airliner during my lifetime (and I plan on living a long time).