Originally Posted by
KenV
Is it? Really? The autothrottle system was dependent on the rad alt, so when the radalt failed, the autothrottle failed. The flight crew is not dependent on the radalt. Changing the above statement slightly results in the following truism: The concept that a flight crew would just stay asleep when the speed was 30 knots below Vref is ludicrous.
I would also suggest that during the design and certification of the system, the safety analysis assumed a trained and competent aircrew, too. With hardly any change in such assumptions from the 60's and 70's.
In my opinion, the last three decades of design and operational use of automated systems in the flight deck has gradually led to less vigilant instrument pilots. Everything works so well, almost all of the time, and when it doesn't it may not be obvious, except to a vigilant grew watching the instruments instead of the system.
I don't blame the pilots, they are the victims of this systematic paradigm shift. Considering how important airspeed control is during the final approach, who would have guessed that pilots would be so inattentive (for two minutes, and this isn't the only such accident)? Unless you have been in the situation after hundreds (thousands) of approaches when "other things" held their attention, and nothing went wrong.
Think how much "better" things will become when airlines achieve their goal of single pilot airline crews, and/or "warm body" co-pilots.