Boeing’s controversial anti-stall system, which was implicated in the crash of a 737 MAX 8 airliner in Indonesia in October last year, was also activated shortly before an accident this month in Ethiopia, a source with knowledge of the investigation said on Friday.
The information is among the preliminary findings from the analysis of the “black boxes” retrieved from Ethiopian Airlines Flight 302, which crashed southeast of Addis Ababa on March 10, killing 157 people, the source told reporters on condition of anonymity.
The information retrieved from the plane’s voice and data recorders was on Thursday presented to US authorities, including the US Federal Aviation Administration (FAA), the source said.
However, the investigation is still under way and the findings are not yet definitive, they added.
The information was first reported by the Wall Street Journal.
Boeing and the FAA declined to comment.
Ethiopian authorities have promised to submit the preliminary report on Flight 302 by the middle of next month, but have already said that there are “clear similarities” between the two MAX 8 crashes.
It was yet another blow to aviation giant Boeing, which just this week unveiled a fix to the Maneuvering Characteristics Augmentation System (MCAS) that it designed to prevent stalls in its new plane.
The planemaker has tried to restore its battered reputation, even while continuing to insist that the MAX is safe.
The family of 31-year-old Jackson Musoni, a Rwandan who died in the Ethiopian Airlines accident, on Thursday filed a lawsuit against Boeing in a court in Chicago, where the company has its corporate headquarters.
The suit accuses the company of designing a defective system.
The MCAS, which lowers the aircraft’s nose if it detects a stall or loss of airspeed, was developed specifically for the 737 MAX, which has heavier engines than its predecessor, creating aerodynamic issues.
The initial investigation into the Lion Air crash in Indonesia, which killed all 189 people on board, found that an “angle of attack” (AOA) sensor failed, but continued to transmit erroneous information to the MCAS.
The pilot tried repeatedly to regain control and pull the nose up, but the plane crashed into the ocean.
The flight track of the doomed Ethiopian Airlines flight, which also crashed minutes after takeoff, “was very similar to Lion Air [indicating] there was very possibly a link between the two flights,” FAA acting chief Daniel Elwell told the US Congress this week.
The FAA grounded the MAX fleet worldwide, but not until two days after most countries had done so.
That delay, along with an FAA policy allowing Boeing to certify some of its own safety features, has raised questions about whether US regulators are too close to the industry.
Elwell denied that the agency was lax in its oversight, saying: “The certification process was detailed and thorough.”
He also seemed to cast doubt on the MCAS as the clear culprit, saying that data collected from 57,000 flights in the US since the MAX was introduced in 2017 revealed not a single reported MCAS malfunction.
However, Steven Marks, the lawyer for Jackson Musoni’s family, said information from the recent tragedies, as well as pilot reports, “made it crystal clear that the cause of these two crashes are the same.”