Originally Posted by
gums
I shall still maintain that the PF and the PNF were thinking that HAL would "protect" them from extreme AoA, even tho' the stall warning was displayed over and over.
I say again - the PNF knew they were in Alternate, so he should (and probably did) know that there were no hard protections from that point.
The grey areas are where procedures and drills meet human psychology, especially the facet of human psychology that instinctively tries to deny that the problem or danger could be as great as it is. We saw it at Tenerife when the F/O and F/E let the Captain take off despite both of them being unsure of their safety, we saw it with Birgenair 301 when the two F/Os could see what was happening and yet did not physically take control and - outside of aviation - we saw it twice at Chernobyl when the shift leader refused to believe that his bungling the safety test could have destroyed the reactor, and later when the plant director ignored the level of radiation leakage from the portable equipment (which indicated 15,000 roentgens/hr), instead preferring to believe that it was at a relatively safe level as indicated by the plant's equipment (which went off the scale at 3.6 roentgens/hr).
Another potential HF issue recalls the Kegworth crash, when radio calls distracted the crew from performing troubleshooting that could have clued them into shutting the wrong engine down. The AF447 PNF was clearly monitoring the ECAM initially, but his attention was drawn away by the attitude of the aircraft following the PF's stick inputs.