LONDON – On Tuesday 27 December, the National Transportation Safety Board (NTSB) published the comments it provided to the Ethiopian government on their draft accident investigation report into the 2019 crash in Ethiopia of a Boeing 737 Max airplane.
The NTSB critique and associated statement has noted that the Ethiopian regulator’s final report failed to include comments provided by the NTSB and misstated other documents and findings in assessing the blame to Boeing.
The US regulator further observes that whilst the Ethiopian report considered the Boeing 737 MAX system design issues which contributed to the fatal accident, it did not appropriately address the human factors which also contributed.
Operational and human factors aspects of the accident
The NTSB response to the Ethiopian regulators accident findings notes the findings of technical and system design issues leading to the fatal crash, however it suggests that human factors as a contributor to the accident have not been appropriately addressed:
“We agree that the uncommanded nose-down inputs from the airplane’s MCAS system should be part of the probable cause for this accident.”
“However, the draft probable cause indicates that the MCAS alone caused the airplane to be “unrecoverable,” and we believe that the probable cause also needs to acknowledge that appropriate crew management of the event,”
“Per the procedures that existed at the time, would have allowed the crew to recover the airplane even when faced with the uncommanded nose-down inputs.”
The NTSB goes on in their response to stress the human factors that should have been addressed:
“Flight crew performance played a critical role in the accident sequence; however, a discussion of the accident flight crew’s performance (including CRM) was not sufficiently developed in the EAIB draft report, which continues to focus heavily on system design issues.”
“The absence of flight crew performance information limits the opportunity to address broader and equally important safety issues.”
“Further, evaluation of the crew’s performance would not have been particularly difficult because the relevant data were readily available in the CVR, FDR, airline manuals/procedures, crew training records, and post-accident interviews.”
The NTSB took the unusual step of publishing the comments on its website after Ethiopia’s Aircraft Accident Investigation Bureau (EAIB) failed to include the NTSB’s comments in its final report.
The latest statement by the NTSB is provided below:
The EAIB recently concluded its investigation into the March 10, 2019, crash of Ethiopian Airlines flight 302, a Boeing 737-800 MAX. The NTSB received the EAIB final accident report on December 27.
In accordance with the provisions of the International Civil Aviation Organization Annex 13, countries participating in the investigation are provided the opportunity to review the draft report and provide comments to the investigative authority.
If the investigating authority disagrees with the comments or declines to integrate them into the accident report, participating countries are entitled to request that their comments be appended to the final report.
The EAIB provided the NTSB with its first draft of the report last year. The NTSB reviewed the report and provided comments on several aspects of the accident the NTSB believed were insufficiently addressed in the draft report. The comments primarily were focused on areas related to human factors.
After the EAIB reviewed the comments, it provided the NTSB with a revised draft report for its review. The NTSB determined the revised report failed to sufficiently address its comments.
As provided by the ICAO Annex 13 process, the NTSB provided the EAIB with more expansive and detailed comments.
Instead of incorporating the most recent and expanded comments into their report, or appending them as had been requested, the EAIB included a hyperlink in their final report to an earlier and now outdated version of the NTSB’s comments.
The NTSB also noted that the final report included significant changes from the last draft the EAIB provided the NTSB.
As a result, the NTSB is in the process of carefully reviewing the EAIB final report to determine if there are any other comments that may be necessary.
The NTSB’s full comments are available online.