IF789
If the descent was transient, and chronic, why shouldn't the THS react with 13 degrees nose up?
Transient as in intermittent, and Chronic as in trend. Both. Pilots do this often, tweak, wait, tweak, wait ad ab. Another term could be: Hunting.
BEA report the THS moved from 3 - 13 degrees. Three degrees could mean sometime before the a/p is lost. This fits in with one excursion only, and could include both a/p and PF inputs, separated by the drop.
"...So they were trained not only not to touch the trim wheel, but also that if they concentrated hard enough, it would actually disappear ?
To me, some of the scariest comments on these threads have been on training practices. Was PFs only training for stall warning "pull up" (to minimize alt loss) ? That is all it would take..."
The pullup at STALL may mimic an artifact in training (not changed til after 447 went in) where the "Recovery" is w/o excessive altitude loss.Where was the added Thrust?
Turbulence? There is nothing in this sequence (sic) to base a conclusion of PF chronic NU. BEA say ".......A INPUT....."
you say
and indeed they don't specify a duration, however the next mention of inputs is nose down after the (first) climb.
During that first climb PF gets stall warning. At 37500ft he gets stall warning again and "maintains" NU input in response. If the response to the SW is consistent, then the conclusion is chronic PF NU.
If the THS had some excess NU, and PF added more NU at handover, what is to say he was not attempting his trained recovery. At STALLSTALL he would NOT immediately input ND but per SOP he would maintain "pull" to minimize altitude loss, not knowing his meager ND, (relaxed back pressure) was way insufficient to keep from Stalling.
He may have actually input Nose down, but it was not beyond neutral and was "READ" as NU by the FMC? He may have been trying to fly with elevators "Only", (not knowing NU/ND would react completely different in response) that would be his set from Stall Training? He certainly didn't train approach to STALL with 13 degrees of THS NU.
At this point, would he become a little unnerved at the reaction to seemingly "appropriate inputs. He would be getting large (and variable and delayed) actions from his hybrid elevator, Tail Plane mongrel. Once again, was his continuous back pressure on the way down his stubborn insistence on his reaction to the a/c at this point (Pull Back, Nose drops, Push, Nose raise?)
If so, at what point was the "feel" of the a/c so foreign to him that he acted in "unpredictable" ways?
thanks for the response
