Report faults design and staff conduct
Boeing thought pilots respond within three seconds of a system malfunction
Indonesia has called for better Boeing cockpit systems and oversight by US regulators after design flaws helped bring down a Lion Air 737 MAX jet a crash that was compounded by errors from ground staff and crew.
In its final report into the crash of the jet on October 29, 2018 that killed all 189 people on board, Indonesia made recommendations to Boeing, Lion Air, the US Federal Aviation Administration (FAA) and other agencies.
It was released on Friday.
Less than five months after the Lion Air accident, an Ethiopian Airlines 737 MAX crashed, leading to a global grounding of the model and a growing crisis for the world’s biggest plane maker, which has just ousted the top executive of its commercial planes division.
In the report, Indonesian regulators criticised the design of the anti-stall system known as MCAS, which automatically pushed the plane’s nose down, leaving pilots fighting for control.
During the flight, the control column was in such disarray that it required 47kg of strength to counter the automated system.
“The design and certification of the MCAS did not adequately consider the likelihood of loss of control of the aircraft,” the report said.
Boeing has been working on a redesign of the MCAS, though it has yet to certified by the FAA.
The report also said “deficiencies” in the flight crew’s communication and manual control of the aircraft had contributed to the crash, as had alerts and distractions in the cockpit.
During the flight, the first officer was unable to quickly identify a checklist in a handbook or perform tasks he should have had memorised, it 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, it also said.
The report noted that according to the cockpit voice recorder, the first officer told the captain the flight was not in his initial schedule and he had been called at 4am to be informed of the revision, while the captain said he had the flu.
A critical sensor providing data to an antistall system had been miscalibrated by a repair shop in Florida and there were strong indications that it was not tested during installation by Lion Air maintenance staff, the report said.
Lion Air should have grounded the jet after faults on earlier flights, it said, and added that 31 pages were missing from the airline’s October maintenance logs.
Lion Air declined to comment. Boeing and the FAA declined to comment before the release of the report.
Boeing faces a slew of investigations by regulators, US Congress, and the Department of Justice over its development of the 737 MAX, its previously best-selling workhorse for short-haul travel.
Boeing CEO Dennis Muilenburg said this week the company was making “daily” progress on testing the final software fix for the 737 MAX and developing related training materials.
The FAA has said it would need at least several more weeks for review.
The Indonesia report also said that Boeing’s safety assessment assumed pilots would respond within three seconds of a system malfunction but on the accident flight and one that experienced the same problem the prior evening, it took both crews about eight seconds to respond.
It called for the systems to be designed not just for highly skilled test pilots but also for regular commercial airline pilots.
The FAA had delegated increasing authority to Boeing to certify the safety of its own aircraft, Indonesian investigators said in the report, recommending that all certification processes were provided with adequate oversight.
A panel of international air safety regulators this month also faulted Boeing for assumptions it made in designing the 737 MAX and found areas where Boeing could improve processes.