Indonesian investigators criticised the design of the anti-stall system known as MCAS, which automatically pushed the plane’s nose down, leaving pilots fighting for control, in its final report into the October 29, 2018, Lion Air crash that killed all 189 people on board.
The report also said “deficiencies” in the flight crew’s communication and manual control of the aircraft contributed to the crash, as did alerts and distractions in the cockpit.
The accident had been caused by a complex chain of events, Indonesian air accident investigator Nurcahyo Utomo told reporters at a news conference, repeatedly declining to be drawn on providing a single dominant cause.
During the flight, the first officer was unable to quickly identify a checklist in a handbook or perform tasks he should have had memorised, he said, adding that he had also performed poorly in training exercises. The captain did not properly brief the first officer when handing over control just before the plane entered a fatal dive, the report also said.
The fatal crash, followed less than five months by another at Ethiopian Airlines, led to a global grounding of the Boeing 737 MAX and a crisis for the world’s biggest planemaker, which this week ousted its commercial airplanes chief.
(Production: Adi Kurniawan, Sekar Nasly, Angie Teo)