WASHINGTON • Investigators looking into a Boeing 737 Max crash in Ethiopia that killed 157 people have reached a preliminary conclusion that an anti-stall system was activated before the plane hit the ground, the Wall Street Journal reported yesterday.
US safety investigators have reviewed data from the "black boxes" that were aboard Ethiopian Airlines Flight 302, four people briefed on the investigation told Reuters on Thursday.
A preliminary report is expected as early as next week, the officials said.
The plane crashed on March 10, shortly after taking off from Addis Ababa.
Investigators of the deadly 737 Max crash in Indonesia in October last year have also focused on the new anti-stall system, called MCAS.
US and European regulators knew at least two years before the Indonesian crash that the usual method for controlling the aircraft's nose angle might not work in conditions similar to those in both disasters, Reuters reported yesterday, citing a document from the European Aviation and Space Agency (EASA).
EASA had certified the aircraft as safe in part because it said additional procedures and training would "clearly explain" to pilots the "unusual" situations in which they would need to manipulate a rarely used manual wheel to control, or "trim", the plane's angle.
Those situations, however, were not listed in the flight manual, according to a copy from American Airlines seen by Reuters.
Boeing declined to comment on the EASA document.
The planemaker's fastest-selling 737 Max jet, with orders worth more than US$500 billion (S$678 billion) at list prices, has been grounded globally by the Federal Aviation Administration and other regulators.
Boeing said on Wednesday that a planned software fix would prevent repeated operation of the anti-stall system at the centre of safety concerns.