Originally Posted by henra
Originally Posted by xcitation
The inexperienced PF did try stick forward however a/c still stays nose up no response, as elevator is at -30 deg due to full THS! So behaviour is bizarre and only explained if you have a full understanding of the situation in 60 seconds.
Hmmm, where did you find this situation in the plots ????
Where was any indication the PF was trying to get the Nose down ??
In contrary the Nose descended a couple of times despite continued NU commands from the PF, albeit slightly reduced from full NU to half NU a couple of times.
In the last minute the PF even fought the ND commands of the PNF by himself applying Full NU.
Having a look at the traces I do not see anything there which would confirm your assertion that the PF was seriously trying to get the nose down.
English BEA #3, Page 111, t>=02:11:00
Locate the 4 lines conveniently next to each other.
brick read, purple, cyan and green.
(brick-red line) look at PF nose downs (+ve above zero),
(purple) elevator max deflection down (forcing nose up)
(cyan) because the THS is auto trimming.
(green) the pitch stays nose up,
Example
t=02:12:17
stick 2/3 (10/16) forward deflection.
elevator -30 deg
THS -13 deg
pitch +4 deg.
My point is that the a/c sometimes did the opposite of inputs (pitch up with stick forward and pitch down with stick back). This was because a/c was dancing around edge of the stall from the outside of the flight envelope.
I stated this because someone said that you could just fly it by behaviour. The behaviour was terrible i.e. inconsistent and at times contrary to stick inputs. A/c needed to be flown by pitch and power with manual THS trim not by its behaviour.
Another point to make is that the instruments were impared, e.g. IAS, altitude etc. The true air speed and true altitude could have been different as noted by the QF72 incidents CPT.