The first report into the Ethiopian Airline’s disaster has found the flight experienced “nose dive conditions” before the crash.
The report, which was released on Wednesday, also absolved pilots of any blame in the crash.
The report stated that the pilots of the doomed aircraft followed proper guidance but could not control the Boeing 737 MAX 8 jetliner last month.
The jet crashed on March 10 shortly after take-off from Addis Ababa, killing all 157 on board.
It was the second crash of a 737 MAX within five months, following a Lion Air crash in Indonesia.
In a clear indication of where Ethiopian investigators are focusing most of their attention, the report cleared the pilots of using incorrect procedures and issued two recommendations directed at plane maker Boeing and regulators.
“The crew performed all the procedures repeatedly provided by the manufacturer but was not able to control the aircraft,” Ethiopia’s Transport Minister Dagmawit Moges said as she delivered the official report.
A statement from the airline said flight 302 repeatedly nose-dived before it crashed, citing the preliminary report.
“Despite all their hard work and full compliance with emergency procedures, it was very unfortunate that they could not recover the aeroplane from the persistence [of] nose-diving,” the airline’s statement on Twitter said.
Ms Moges recommended Boeing review the aircraft control system and that aviation authorities confirm the problem had been solved before allowing that model of the plane back into the air.
The 737 MAX 8 was grounded globally following the crash, which was the second deadly accident in six months involving the new model.
“Since repetitive uncommanded aircraft nose down conditions are noticed … it is recommended that the aircraft control system shall be reviewed by the manufacturer,” Ms Moges said.
Ethiopian investigators cannot yet say whether there is a structural problem with the jetliner, based on flight and cockpit voice data from the fatal crash.
Read also: Newspaper vendor hangs self over debt
“We will analyse whether other problems were existing on this aircraft,” Amdye Ayalew Fanta told a news conference, adding this would take between six months and a year.
In line with international rules on air accidents, the preliminary report did not attribute blame. Nor did it give a detailed analysis of the flight, which is expected to take several months before a final report due within a year.
However, the report could spark a debate with Boeing about how crew responded to problems triggered by faulty data from an airflow sensor, particularly over whether they steadied the plane before turning key software off.
Families of the 157 victims, regulators and travellers around the world are waiting for clues to the accident after the new Boeing jet crashed six minutes after take-off.
Boeing declined to comment pending its review of the preliminary report.
The preliminary report into the Lion Air disaster said the pilots lost control after grappling with the aircraft’s Manoeuvring Characteristics Augmentation System (MCAS) software, a new automated anti-stall feature that repeatedly lowered the nose of the aircraft based on faulty data from a sensor.
Boeing said it had successfully tested an update of the MCAS software designed to reduce its authority and make it easer for pilots to handle.
The plane maker is the focus of investigations by the US Justice Department, the Transportation Department’s inspector general, and congressional committees.
Investigations are also looking at the role of the Federal Aviation Administration (FAA) in the US, which certified the MAX in 2017 and declined to ground it after the first deadly crash in October.
The FAA said in a statement that it is continuing to work toward a full understanding of what happened and will take appropriate action as findings become available.