Joe Sedor, the National Transportation Safety Board official who led the American team working on the Turkish Airlines investigation, said it was not unusual for investigating bodies to make changes to a report after receiving feedback, or for American safety officials to jointly submit their comments with Boeing.
Mr. Sedor is now overseeing the N.T.S.B.’s work on the Max crashes. He acknowledged that reliance on a single sensor was a contributing factor in both cases but cautioned against focusing on it.
“Each of these accidents were complex and dynamic events with many contributing factors,” he said. “Boiling them down simply to the number of inputs ignores the many, many more issues that differentiate them.”
The F.A.A., in a statement, also emphasized the “unique set of circumstances” surrounding each accident. “Drawing broad connections between accidents involving different types of emergencies oversimplifies what is, by definition, a complex science,” it said.
The agency, also part of the American team in the Dutch investigation, declined to say whether the lessons from the Turkish Airlines crash factored into its decision to certify the Max — which was approved to fly in 2017 and became the fastest-selling plane in Boeing’s history.
But a senior F.A.A. official, who was not authorized to speak publicly, praised Dr. Dekker’s study and said it identified important issues that had not received enough public attention. The official pointed to the similarities — such as the reliance on a single sensor — between the Turkish Airlines crash and the Max accidents.
A spokeswoman for the Dutch board, Sara Vernooij, said it was common practice to amend draft reports in response to outside comments, but she declined to address the specific changes. Other companies and government bodies involved in the investigation, such as the French firm that made the sensors and that country’s aviation safety board, also submitted comments, but the American submission was the most extensive.