Investigators are examining the crashes that killed all 346 aboard the 737 Max 8 jets operated by Indonesia's Lion Air and Ethiopian Airlines, including the role of a flight-control system called MCAS, which under some circumstances could automatically turn the plane's nose down to prevent an aerodynamic stall.
The Journal reported that data downloaded from the plane's black boxes indicates that the Ethiopian Airlines pilots followed recommendations to flip two switches that disconnected the system, but the plane kept sinking.
They turned a manual wheel that adjusts the plane's tail, and used electric switches in an effort to climb, but that reactivated MCAS, which continued to push the plane's nose lower.
Ethiopian investigators are expected to release their preliminary findings in the next few days.
Boeing is the focus of investigations by the Justice Department, the Transportation Department's inspector general, and congressional committees.
Investigations are also looking at the role of the Federal Aviation Administration, which certified the Max in 2017 and declined to ground it after the first deadly crash in October.
- AP