The chairman of the US National Transportation Safety Board says a preliminary report on the Ethiopian Airlines Boeing 737 Max 8 crash was "very thorough", even as he cautions that information could well change following the release of the initial findings.
"I thought the report was very thorough and well done," Robert Sumwalt told reporters following the Aero Club luncheon in Washington DC earlier today.
"I applaud the Ethiopian government for coming up with it within not a lot of time, which was 30 days," adds Sumwalt, calling the report "a very comprehensive job".
Sumwalt, however, urges the industry to refrain from speculating on the cause of the 10 March crash, telling the audience at the luncheon: "The only caveat i can put on that is that it's a preliminary report and things can change."
NTSB sent representatives to participate in the investigations into the Ethiopian crash and the October 2018 crash of a Lion Air 737 Max 8 in Indonesia that went down in similar circumstances.
Preliminary reports into both incidents had highlighted erroneous angle-of-attack sensor readings, and repeated instances of the aircraft pitching nose-down automatically. Attention has focused around the aircraft's Manoeuvring Characteristics Augmentation System (MCAS) – a system new to the 737 Max and not found on earlier 737 variants – and how it could have activated in response to the erroneous readings.
Boeing started developing a software update for MCAS following the Lion Air crash, and said in recent days it is working to have the update certified by regulators.
Sumwalt declines to comment on whether Boeing could have moved faster on the software update after the Lion Air incident, saying that the NTSB was not involved in the US Federal Aviation Administration's decision to ground the 737 Max on 13 March, aside from validating data from the Ethiopian flight to help the FAA make an informed decision.
"That's an issue for the regulator [the FAA]," he says. "That's not in our lane."