The technical, design, and certification aspects emerging from this accident are similar to other high profile accidents.
A ‘first-pass’ evaluation avoiding blinding thoughts of error, identifies that the ‘initiating’ factors were technical malfunctions (also AF447, Swedish CRJ, 737 AMS). Subsequently, ‘enabling’ factors which determine if the event was recoverable or not, depend on the assumptions relating to awareness, knowledge, and human intervention.
It would be interesting to understand how the design Failure Mode Effect Analysis (FMEA) dealt with an erroneous AoA input. What was assumed about the overall system integrity, failure frequency, and obviously the effect. And for the latter, what human contribution was assumed in mitigation.
From the AD, it appears that there is now concern about awareness and meaning of the multiple alerts and range of instruments / systems affected; the difficulty for the crew to make sense of the overall situation. If there is a specific checklist, is it dependent on situation, context, or that crew performance would alway be adequate?
In certification, what was assumed about input systems, normal or failed, not requiring ‘significant pilot strength, awareness, or attention’ (or similar judgemental text more often divorced from operational context)?
In airworthiness, how many previous sensor failures, consequential events; what analysis was made / tracked. What was assumed in this process, assembling isolated features requiring in-depth system knowledge to foresee and circumvent an accident?
In mitigation, will the AD information and check list be enough to counter the adverse effects as above; is this also an assumption that crews will now manage all future encounters, in all foreseeable circumstances, in every context? Or is this still a judgement, a short-term gamble ?