automation and feedback
Thank you Safety, thank you. The Norman paper is appropriate and a necessary "read" for all here.
Before adding to 'bird's ideas, I must point out that the accident started when air data sensors went south.
So what do we do when that happens? What do we do when the A/P disconnects and autothrottle keeps power setting where it was?
Well, it depends upon the design of the flight control system (FCS), old fashioned or the new FBW systems. It also depends upon crew training and "attitude" of the crew.
As a pilot, I would prefer a more straightforward reversion sequence, similar to 'bird's #1.. No need to go straight to the "direct" law where electrons simply replace tubes, cables and hydraulic lines. Just revert to a very basic "control stick steering" (CSS) and replace insistent efforts by the FCS to "protect you". Provide warning and caution indications of mach, AoA, etc when available, but basically fly attitude that is available from embedded sensors in the FCS. In other words, you have a very capable autopilot type function and have time to assess the loss of air data while maintaining aircraft control. Retired, 'bird, Smilin' and others here have flown with CSS, and it is easy.
Inherent in a FBW system are embedded sensors we used to use for attitude and navigation/weapon delivery. When the confusers fail, these sensors also fail or are ignored, You are SOL at that point. Meanwhile, you should have body rate, acceleration and even attitude sensors embedded. e.g if. you don't depend upon the external navigation/autopilot sensors - inertial, GPS, doppler, pitot-static, AoA vanes/cones, AHRS, etc.
We don't need a "wing leveler", just a "hold the roll and pitch angle when control pressure/movement is relaxed". Throttle/power is manual. You can even have the gee command active and the roll rate command active when you move the stick, as they are inherent in the FBW system.
So reflecting upon Norman's outstanding discussion of feedback in automated systems, that's my story and I'm stickin' to it. He was too early for the AA regional ATR accident when the A/P was feeding in control deflection due to ice build up. When all went to hell in a handbasket, Sad sad, and there was also some distractions in the cockpit for ten or fifteen minutes before A/P disconnect.
Bottom line is there are too many "external" inputs to the FCS after the air data has failed, and the spurious stall warnings and such did not help the crew. With a straightforward reversion to a CSS type system, I think the crew would have handled the situatin better. I do not excuse the pilot's mysterious nose up commands for so long before the aircraft entered Chuck Yeager territory.