Workers walk past flowers laid at the scene where the Ethiopian Airlines Boeing 737 Max 8 crashed shortly after takeoff, killing all 157 on board, near Bishoftu, or Debre Zeit, south of Addis Ababa, in Ethiopia, on March 13, 2019. (MULUGETA AYENE / AP)

WASHINGTON/SEATTLE - A US House investigative report into two fatal Lion Air and Ethiopian Airlines crashes on a Boeing 737 MAX faulted the Federal Aviation Administration’s (FAA) approval of the plane and Boeing’s design failures, saying the flights were “doomed.”

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Boeing Co’s (BA.N) 737 MAX has been grounded worldwide for nearly a year following the second of two crashes, one in Indonesia in October 2018 and one in Ethiopia last March, that together killed 346 people.

The preliminary investigative findings called the FAA’s certification review of the 737 MAX “grossly insufficient” and said the agency had failed in its duty to identify key safety problems

The preliminary investigative findings from the US House Transportation Committee, released on Friday, called the FAA’s certification review of the 737 MAX “grossly insufficient” and said the agency had failed in its duty to identify key safety problems. 

“The combination of these problems doomed the Lion Air and Ethiopian Airlines flights,” the panel said in the 13-page report.

It also said Boeing’s 737 MAX design “was marred by technical design failures, lack of transparency with both regulators and customers, and efforts to obfuscate information about the operation of the aircraft.

The report, which comes days ahead of the anniversary of the Ethiopian Airlines crash, adds that the findings should prompt legislative changes to address how US regulators approve new aircraft for service.

The committee has been probing the crash for almost a year and received hundreds of thousands of documents and interviewed key Boeing and FAA employees in its investigation.

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Boeing said it has cooperated extensively with the committee’s investigation and said it would review the report.

The FAA said in a statement it welcomed the report’s observations and said lessons learned from the two fatal crashes “will be a springboard to an even greater level of safety.”