LO
ConstraintCognitive automation2019-09-19
Crews facing multiple alerts from a faulty sensor lacked tools to find the most effective response, and pilots' reactions did not match the design's assumptions: NTSB on the 737 MAX
Airline pilotoccupation page →
Event date / reported
2019-09-19
Evidence stage
ConstraintFailure, rollback, regulation or cost is suppressing adoption. Can lower an assessment or widen its uncertainty.
Tasks this bears on
When two systems disagree
An engine failure, a decompression, a warning that contradicts another warning, weather that closes the destination after the point where you could have gone elsewhere.
Still human-led✓ Evidence-backed
Where this applies
A safety recommendation report by the US accident investigator following two Boeing 737 MAX accidents. It finds that in all three flights reviewed, pilot responses differed and did not match the assumptions about pilot responses to unintended activation of the automated flight-control function on which Boeing based its hazard classifications, and that the erroneous angle-of-attack output produced multiple alerts and indications, yet the crews lacked tools to identify the most effective response. It is based on the preliminary accident reports, and its recommendations bind no one.
What this means
When the automation misbehaved, the abnormal case landed on the crew — and the design had assumed a cleaner response than real crews could give under a cascade of alerts. The lesson drawn was to design for the people handling the failure, not around them.
What it does not yet show
Based on preliminary reports of two accidents with one aircraft type; recommendations, not rules.
What you can check
Open NTSB Safety Recommendation Report ASR-19-01 and find "the crews lacked tools to identify the most effective response".
Does it change the assessment?
No. The impact index is never moved by a single event. Nor did this record change a layer: all 1 linked judgement above already rested on earlier evidence. This one adds to them.
Source
U.S. National Transportation Safety Board — Safety Recommendation Report ASR-19-01, Assumptions Used in the Safety Assessment Process and the Effects of Multiple Alerts and Indications on Pilot Performance (Report Date: September 19, 2019) · verified 2026-09-29 · Claude (VOLO agent) · interpreted 2026-09-29 · Claude (VOLO agent)
Primary source — published by the party that did this, or the authority of record. No co-signature needed.