Originally Posted by
iceman50
EcamSurprise
My only comment would be who initiated the nose down input! .
I would assume that the A350 (which I haven't flown) is pretty much the same as the A330 and A340 (which I have flown) in that the Stabilizer (auto trim) freezes at 100 feet RA for the FCS Flare Mode. That leaves only the elevators controlled by the sidestick to flare the aircraft.
At the instant that the Stabilizer freezes, it could be out-of-trim, depending on the conditions experienced passing 100 feet RA. That is, if a large up or down pilot sidestick command was taking place, thrust was above or below the mean, airspeed was above or below VAPP, and rate of descent higher or lower than the mean.
With the Stabilizer in an out-of-the trim position, unusual push or pull force is required on the sidestick to maintain the required vertical profile and again, unusual stick force to accomplish the desired flare manoeuvre.
With due regard to the control system Flare Mode action of the Stabilizer, in gusty conditions, the aircraft response can surprise pilots with an unexpected change in rate of descent, especially when the Stabilizer is frozen Aircraft Nose Down, and then the arse falls out of it.
If the A350 does not have the same FCS Flare mode as the A330/A340 regards the Stabilizer...then please ignore all above.