Both Reuters and The Wall Street Journal report that the air crew followed procedures laid out by Boeing following the crash of a Lion Air 737 MAX in October, according to officials briefed on the initial findings of the investigation. But the pilots failed to regain control of the system, and the MCAS was reactivated again—triggering yet another automated correction of the aircraft’s stabilizers that would have pushed the nose of the plane down.

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To prevent the MCAS from continually pushing the nose down in the event of bad sensor data or some other software failure, Boeing instructed pilots to deactivate the system using procedures already in place for dealing with runaway stabilizer control systems in other 737 aircraft—flipping two stabilizer trim “cutout” switches to the “cutout” position. Failure to do so could result in the system pushing the stabilizers to their movement limit—putting the aircraft into a steep dive. The pilots of the Ethiopian Airlines flight did flip the cutout switches, and they cranked the controls to attempt to regain positive stabilizer control. But they continued to have difficulty controlling the aircraft.

It is not clear at this point whether the pilots purposely reactivated the MCAS’ stabilizer control or if the software reactivated on its own after shutdown. While a Wall Street Journal source said that it appeared the pilots turned the system back on in hopes of regaining control over the stabilizers, Reuters reports that the software may have reactivated without human intervention, and further investigations of that possibility are ongoing.

The flight crew on the Ethiopian Airlines aircraft followed at least part of a protocol set by planemaker Boeing Co. to manually disable an automated anti-stall system as they tried to save the 737 Max jet, a person familiar with the situation said as Ethiopian authorities prepare to release a preliminary report on the accident Thursday.

However, the pilots didn’t perform another critical part of the checklist, said another person familiar with results of the Ethiopian investigation. Before cutting power to a motor operated by the Maneuvering Characteristics Augmentation System, they failed to adjust the plane so it wasn’t set to dive. That made it more difficult to fly the plane and may have hastened the fatal plunge that occurred later in the flight, said the person, who wasn’t authorized to speak and asked not to be identified.

The pilots later switched power back on to the so-called trim motor, said the person. That runs counter to the warning Boeing and the U.S. Federal Aviation Administration issued last November after the first crash of a 737 Max aircraft in Indonesia. The FAA’s emergency directive says switches controlling power to the trim system should be set to “CUTOUT and stay in the CUTOUT position for the remainder of the flight.”

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MCAS engaged numerous times during the short flight, one of the people said. The software feature, which is programmed to push down a plane’s nose to help prevent aerodynamic stalls in some situations, is a focus of concern by regulators and lawmakers after 346 people died in crashes of Boeing’s newest version of the 737 flown by Ethiopian and Lion Air less than five months apart.

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The American Airlines pilots who flew Boeing simulators last week were surprised at how fast the plane’s trim system tried to push the nose down when MCAS activated, said Dennis Tajer, spokesman for the Allied Pilots Association, which represents pilots at the carrier.

“They were able to disconnect it and were able to use the manual trim, but they said it was a handful. This is a complex emergency,” he said. “To get my trust and confidence in the new software, I have to have some trust issues revisited.”

The doomed Ethiopian Airlines Boeing 737 MAX which crashed shortly after take-off, killing 157 people on board, was struck by a mystery object or bird, according to a leaked report. ...