Indonesia’s Lion Air crash report calls for redesign of Boeing 737 MAX, better training for pilots
- An advance copy of a final report into the crash that killed all 189 people on board last October found a number of issues with the aircraft made by US aviation giant Boeing
- Lion Air should have grounded the jet following faults on earlier flights, it said, adding that 31 pages were missing from October maintenance logs
An advance copy of a final report into the crash of the Boeing 737 MAX that crashed on October 29, 2018 was obtained by The Seattle Times, which published the report.
Indonesian investigators on Wednesday told families of the victims that a mix of factors contributed to the crash, including mechanical and design issues and a lack of documentation about how systems would behave.
“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, according to slides presented to the families.
The final report said the first officer was unfamiliar with procedures and had shown issues handling the aircraft during training, according to The Seattle Times.
When the aircraft encountered airspeed reading problems after take-off, the first officer had to be asked twice by the captain to perform the checklist and it took him four minutes to find it in the quick reference handbook, the newspaper said.
The report also found that a critical sensor providing data to an anti-stall system had been miscalibrated by a repair shop in Florida and that there were strong indications that it was not tested during installation by Lion Air maintenance staff.
Lion Air should have grounded the jet following faults on earlier flights, the report said, adding that 31 pages were missing from the airline’s October maintenance logs.
Lion Air did not respond to a request for comment.
In the report, Indonesian regulators recommended a redesign of the anti-stall system known as MCAS that automatically pushed the plane’s nose down, leaving pilots fighting for control.
Boeing has already said it would remake the system and provide more information about it in pilot manuals.
According to the report, Boeing’s safety assessment assumed pilots would respond within three seconds of a system malfunction but on the flight that crashed and one that experienced the same problem the previous evening, it took both crews about eight seconds to respond, The Seattle Times said.
Boeing had reasoned that MCAS could be countered by a pilot pulling back on the control column alone, but events and subsequent tests showed that cut-out switches needed to be used, the paper cited the report as saying.
In December 2018, accident investigators and Boeing conducted a simulator test and found that after just two activations of MCAS, absent counteraction from the pilot, the control column became “too heavy” to move, the newspaper said.
The final report will be released publicly on Friday. Boeing has said it cannot comment before the release of the report.
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.
