JD-EE
Bearfoil, is it a total blunder if you have a UAS condition to apply UAS procedures?
Let's turn that around. Why initiate UAS c/l if UAS has not been identified?
It is not until 2:10:16 that PNF notes "lost speeds" then "Alternate Law". The a/p is reported to have been lost at 2:10:05 ("I have controls"). From the release, the pilot is said to have made control inputs after a/p loss, and prior to "Lost speeds". If he was flying in ALT LAW at a/p loss, it would seem he was unaware (if his NU was intended). That is unlikely, so he may have made inputs in what was likely Normal Law. All protections, and fly the a/c by hand, in comfort, but without auto pilot. No big.
Did he pull the stick before the stall warning or after? It appears to be "before" in the rude imprecise chronology of the released data.
I agree, and nothing is noted after the "input", said to be left, NU. At the Stall warning, one would think he would relent on the NU (if he indeed knew he was inputting NU) but continue levelling the wings, already underway.
And simply for my own information I have some related questions.
* If he should have waited to apply UAS procedures then how long should he have waited?
Once again, it is not known (though it is strongly suggested) that the a/c had dropped into ALAW, and his wing levelling (and Pitch correction, if intended) was appropriate. At this juncture, it is not known whether the PF continued with his initial corrections, as BEA Say:"...PF made
one input...."
* What is the intended purpose of the UAS procedure. It seems to be to slow down the plane to get it into a safer margins condition between stall and overspeed, which was already happening.
One thing,
afaik, Stability. Each of the logged incidents has a somewhat different and "ad lib" recovery. Here, the argument against BUSS loses credibility, "It eliminates Anemometric input until landing." Well, speeds are gone, and if they come back, fine no need for BUSS? But if they do not, the need is for speed data for a long safe home, and BUSS might be just the thing.
* Might the pilot have asserted the "slow me down quickly" planning to lose maybe 50 knots by climbing 500' to 1000' and then level off only to have the stall warning derail his thought processes?
I doubt it. The consensus at brief was climbing was ill advised, due warm temps. But that was for a discretionary climb, and as you say, the need for urgent loss of velocity is not eliminated.
* Is everyone happy with the UAS scenario PJ2 suggests?
I am. It was PJ2 who let me know that a vanilla loss of autopilot does not degrade Law, the ship stays in Normal. Now "A/S reads unreliable" was noted eleven seconds after a/p drop. If uas was the deal, a/p would have been dropped at AD disagree, and that would have occurred, of course, prior to loss of autopilot. "I have controls" (after loss of a/p) is first, "Alternate Law" 11 seconds after. It may be merely an anomaly of CVR. I have not seen it explained yet, however.
One does not know, without DFDR data, the accelerations on and around the airframe. A/P disconnect is the first item on UAS c/l. Airbus does it automatically. The AutoPilot also drops out when it cannot keep up with its own manuevering limits.