NEW YORK — Ethiopian officials on Thursday are expected to release preliminary conclusions in the probe of last month's crash of a Boeing 737 that killed 157 people, two sources said on Wednesday.

The report on the March 10 crash on the Ethiopian Airlines plane could be published late Thursday morning in Ethiopia, said the sources close to the investigation, who spoke on the condition of anonymity.

News of the report's impending release came as the Federal Aviation Administration announced a new review of the 737 MAX and as the head of Boeing joined a test flight designed to demonstrate the effectiveness of the company's proposed fix.

Aviation regulators around the world grounded Boeing's 737 MAX last month following the Ethiopian Airways crash, which came less than five months after an October Lion Air crash that killed 189 people.

Scrutiny has centered on an anti-stall system developed specifically for the latest versions of the planes that has given pilots problems.

The Wall Street Journal reported Wednesday that pilots on the doomed Ethiopian plane initially followed emergency steps outlined by Boeing but still could not regain control.

The pilots shut off the anti-stall system, called the Maneuvering Characteristics Augmentation System, but switched it back on because they could not regain control, The Journal reported, citing people briefed on the preliminary findings.

Boeing's CEO personally tests fix

The FAA announced it was establishing a new interagency team to review the certification of the automated flight control system on the 737 MAX.

The group "will evaluate aspects of the 737 MAX automated flight control system, including its design and pilots' interaction with the system, to determine its compliance with all applicable regulations and to identify future enhancements that might be needed," said a spokesman for the FAA, which faced tough questioning at a Senate hearing last week over its relationship with and oversight of Boeing.

The initiative will be chaired by former National Transportation Safety Board Chairman Chris Hall and include experts from the FAA, NASA and international aviation authorities.

Meanwhile Boeing, seeking to win back public confidence in the planes, released photographs of its chief executive, who joined a test flight of a 737 MAX with the company's updated anti-stall system.

The FAA said Monday that Boeing needed to undertake more work on the proposed fix before it could be submitted for review.

Boeing distributed a cockpit photo of Chief Executive Dennis Muilenburg wearing earphones and seated behind two pilots.

A second shot showed the Boeing chief exiting the aircraft at Boeing Field in Washington state.

"The flight crew performed different scenarios that exercised various aspects of the software changes to test failure conditions," the company said.

"The software update worked as designed and the pilots landed safely at Boeing Field."

Boeing said it planned to submit its proposal to the FAA in the coming weeks following "a thorough and disciplined approach to the development and testing" of the enhancements. — AFP