Many thanks for your open-minded approach, Man Flex. It 'spurred me on' to have another read of the Perpignan report which I linked to earlier. I'm afraid that the paragraph immediately preceding the part I quoted does indeed say that the 'systems,' for reasons best known to themselves,
did apparently ignore the pilot's nosedown inputs and leave the THS at 'full up':-
When the stall warning sounded, the Captain reacted by placing the thrust levers in the TO/GA detent and by pitching the aeroplane down, in accordance with procedures. The nose-down input was not however sufficient for the automatic compensation system to vary the position of the horizontal stabilizer, which had been progressively deflected to the pitch-up stop by this system during the deceleration. The Captain controlled a left roll movement, caused by the stall. The aeroplane’s high angle of attack and the roll movements generated asymmetry, and a speed variation between ADR 1 and 2 appeared. This increasing divergence caused a rejection of the three ADRs by the FAC then the ELAC. The flight control system then passed into direct law. It is likely that the crew did not notice this due to the emergency situation and the aural stall warning that covered the warning of a change of flight control laws. The Air New Zealand pilot, by saying “alpha floor, we’re in manual” likely considered that the alpha floor function had triggered and that in fact the autopilot had disconnected.
Golden Rivit, the same paragraph also largely answers your question. As far as I know (Airbus pilots please amplify) when the systems go into 'direct law' a message appears saying "USE MAN. PITCH TRIM" - I don't know whether there is an aural warning as well. But the BEA report concludes that this could well have been 'masked' by all the other warnings that would have been going off by that time.
Man Flex, have to 'come to the defence' of the AF447 pilot. He did indeed apply nosedown stick and get the aeroplane practically level, at Mach 0.68, and at an AoA of only four degrees (that is, near enough 'normal flight'). I'm afraid that it looks increasingly likely that the AF447 THS, like the Perpignan one, ignored the pilot's 'nosedown inputs,' and stayed at full up. Which could very well have both caused and maintained the stall?
The PF made nose-down control inputs and alternately left and right roll inputs. The vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied between 12 degrees right and 10 degrees left. The speed displayed on the left side increased sharply to 215 kt (Mach 0.68). The airplane was then at an altitude of about 37,500 ft and the recorded angle of attack was around 4 degrees.
Anyone know more about that 'automatic compensation system' that the Perpignan report mentions?