sriajuda @ 16:54
I think the goal is definitely not to produce identical pilots, but to train all pilots to minimum standards. The standard is set, though arbitrarily, by other than the crew, and experience and skill are varied, it is human nature.
For example, if there were two identical PF's and one had acquiesced to the other, the result on 447 would have been the same? No, because the position is different, the perspective is different, etc. No matter, it is clear that at least at the start, PNF had the picture correct....
How many have said the PF should have handed over to PNF? Merely looking at route experience, that would be logical.
My point above is meant to demonstrate the benefits of incorporating separate designs into two devices that accomplish the same task on an airliner. What defeated the Thales (microgranular water ICE), historically had less effect on Goodrich, type for type. So in grading the two, Thales is found wanting in ICE resistance; perhaps Goodrich has a different weak spot. Redundancy in the face of common fault is worse than no redundancy at all. Back up with a separate design approach is far better.