Ethiopian probe finds faults in Boeing’s 737 Max design and training

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Flawed software design and inadequate training by Boeing were among the factors that may have contributed to last year’s Ethiopian Airlines 737 Max crash that killed 157 people, including 18 Canadians, an Ethiopian investigation has found.

The 136-page interim report was issued by the Ethiopian government Monday, a day before the anniversary of the crash of Flight 302. Many relatives are planning to gather at the crash site Tuesday for a memorial ceremony.

Boeing’s training for the 737 Max was “found to be inadequate,” the report said.

It called for training to include flight simulator sessions to familiarize pilots with normal and abnormal operation of the airplane’s anti-stall flight system, known as the Manoeuvring Characteristics Augmentation System (MCAS).

The report cited flaws in the MCAS software, saying the system’s design “made it vulnerable to undesired activation.” It said it could be activated by a faulty reading from the plane’s angle-of-attack (AOA) sensor.

“The specific failure modes that could lead to uncommanded MCAS activation, such as an erroneous high AOA input to the MCAS, were not simulated as part of the functional hazard assessment validation tests,” the report said.

"The training simulators need to be capable of simulating AOA failure scenarios,” it added.

The report did not cite any errors by the plane’s flight crew or the airline, despite media reports in which former Ethiopian Airlines employees complained that the airline had failed to pay enough attention to safety. The airline has denied those accusations.

The Ethiopian report comes three days after similar criticism of Boeing in a preliminary report by the U.S. House of Representatives transportation and infrastructures committee, which investigated the Ethiopian crash and an earlier 737 Max crash that killed 189 people aboard a Lion Air flight in Indonesia in 2018.

In both crashes, there were uncontrolled drops in the aircraft’s nose just minutes after takeoff. An official Indonesian report, released last October, cited mistakes by the Lion Air flight crew and airline workers as well as flaws in Boeing’s software.

The two crashes within a span of five months led to the grounding of 737 Max planes worldwide and threw the manufacturer into a crisis that plagues it still. The planes remain grounded, families of the victims have launched hundreds of lawsuits, and the issue has cost Boeing billions of dollars.

The U.S. committee report, released last Friday, pointed to financial pressures at Boeing to cut costs and stay on schedule, along with the company’s “culture of concealment,” as factors in the crashes.

“In several critical instances, Boeing withheld crucial information from the FAA, its customers, and 737 Max pilots,” the committee report said.

Additionally, it said, Boeing improperly classified the MCAS system in a manner that saw it avoid greater scrutiny and exerted influence over the FAA that contributed to the regulator’s “failed” responsibility to protect the public.

Canadian airlines, in the midst of renewing their fleets, were big buyers of the Max, which formed a key plank in their plans to cut operating costs and boost fuel efficiency.

Air Canada, which has 24 of the grounded planes in its fleet and another 26 on order, declined to comment Monday.

The Montreal-based airline has dropped the plane, which accounts for 24 per cent of its narrow-body fleet, from its schedule until June 30.

WestJet Airlines has scrubbed its 13 Max planes from the schedule until June 24, representing about 10 per cent of its passenger capacity.

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