Originally Posted by
OldnGrounded
Thanks. Armchairpilot's link was to a version of the story published in Straits Times and the headline cited ddn't get my attention. I posted the link to the other version largely because "a source" who supposedly heard the CVR recording or read a transcript noted that the crew didn't appear to have noticed the H-stab trimming.
Everything points to 'automation surprise' which occurs when automation does something you do not expect.
See
"Automation Surprise" in Aviation: Real-Time Solutions Here is the abstract:
Conflicts between the pilot and the automation, when pilots detect but do not understand them, cause "automation surprise" situations and jeopardize flight safety. We conducted an experiment in a 3-axis motion flight simulator with 16 pilots equipped with an eye-tracker to analyze their behavior and eye movements during the occurrence of such a situation. The results revealed that this conflict engages participant's attentional abilities resulting in excessive and inefficient visual search patterns. This experiment confirmed the crucial need to design solutions for detecting the occurrence of conflictual situations and to assist the pilots. We therefore proposed an approach to formally identify the occurrence of "automation surprise" conflicts based on the analysis of "silent mode changes" of the autopilot. A demonstrator was implemented and allowed for the automatic trigger of messages in the cockpit that explains the autopilot behavior. We implemented a real-time demonstrator that was tested as a proof-of-concept with 7 subjects facing 3 different conflicts with automation. The results shown the efficacy of this approach which could be implemented in existing cockpits.
MCAS is a 'silent mode change' of the aircraft and so too was the AoA disagree in some ways.
So had there been a warning
"AoA Disagree expect unreliable airspeed, Stick Shaker and MCAS" followed by
"MCAS TRIMMING DOWN"
There would have been no automation surprise as the crew wouldn't have been left trying to find out 'what's it doing now?' and two aircraft could have landed safely.
Indeed just these warnings may be all the software change needed.