olster
The picture I have from the report is that trim automatically went nose up, to the stop.
The pilots were used to depending on auto trim, and didn't think to consider the antagonistic Pitch force thus provided against their wish to drop the nose.
A general concern might be that in slow flight, autotrim (Auto Pilot?) might be unnecessary. The Bus has powered controls, and has a fine "touch" relative to Pitch, at any speed, so why not set Trim at the neutral set, and rely only on elevator, or elevator plus an "articulating" HS? Trim used to be simply a setting that lessened a pilot's effort at the stick, instead of a fully integrated "Variable Incident HS". Whatever the concern, here the trim was in what used to be called "runaway", relative to the pilot's baseline Pitch awareness. As BOAC has said, automatic flight is a boon, an enhancement (great word), but if something gets pear, the pilot needs to know the "mood" of the a/c, and immediately. Any hesitation in alert may cause an unproductive "solution set" in the FP, and want "unwinding" as The Pilot "finally" "gets" the situation. My sense of the AirBus is that it is finely tuned and capable, and resists rapid and large movements, that it is "uncomfortable" in the "unusual". Why wouldn't it be, it is designed for the normal flight. If flightcrew are not well trained in its behaviour at the edge, perhaps the "edge" in a commercial turnover should be explored by the Manufacturer's test flight personnel. The focus of this airframe is docility, and efficiency, and Safety. If it is trained to these goals, and unusual Attitudes and Stall are not "possible" such that these are not trained, a casual decision to test slow flight and protections at very low altitude would be (should be) non existent? I think BOAC has the upshot of this accident fully nailed down, aerodynamically, mechanically, electronically, and even politically.
bear