BA Boeing Co

By Andy Pasztor 

Faulty aircraft design and inadequate pilot-training recommendations from the manufacturer led to the fatal crash of a Boeing Co. 737 MAX jet after takeoff from Addis Ababa in Ethiopia a year ago, according to an accident report issued by Ethiopian investigators.

The interim report released Monday about the crash of Ethiopian Airlines Flight 302 provides some new technical analyses along with details about the cockpit drama before the plunge -- with pilots pulling back on the controls with more than 180 pounds of force to no avail. But the document indicates that neither pilot errors nor potential airline slip-ups contributed significantly to the tragedy that killed all 157 on board.

The findings contrast with a series of other government and industry reports that highlighted the important interplay of causal factors, ranging from Boeing's misguided engineering assumptions to lax regulatory oversight to at least one significant incorrect pilot command.

Monday's report gives short shrift to such contributing causes and focuses largely on Boeing's failings in devising a powerful new automated flight-control feature, called MCAS. That feature, which ended up aggressively and repeatedly pushing down the nose of the Ethiopian airliner, is being fixed before the global MAX fleet returns to service.

The global MAX fleet has been grounded since the March crash, touching off the biggest corporate crisis in Boeing's history and sending ripple effects throughout the aviation industry.

The report mentions but doesn't elaborate on a central question of why Ethiopian pilots, after turning off MCAS as required by an emergency checklist, ultimately flipped a switch that reactivated the feature that overpowered their efforts to pull out of the plane's dive.

Within seconds, the plane became uncontrollable and ended up with its nose pointing down 40 degrees from level flight.

The interim report, among other things, concludes that the heart of the pilot training "provided by the manufacturer was found to be inadequate." It also indicates that certain cockpit alerts, designed to help pilots diagnose sensor malfunctions that could trigger a hazardous MCAS misfire, didn't work as intended or as they were described in the flight-crew operation manual. The final conclusions are expected later this year.

A spokesman for Boeing said the company continues to provide technical assistance in support of the Ethiopian-led investigation and looks forward to "reviewing the full details and formal recommendations that will be included in the final report."

The U.S. Federal Aviation Administration, which has been criticized by congressional investigators and others for delegating too much authority to Boeing in initially vetting safety of the 737 MAX, said it is reviewing the interim findings. An email from a spokesman added: "We believe it's important to have the full final report to evaluate it against other independent reports, so that we might fully understand all of the factors -- both mechanical and human -- that played a role in this tragic loss of life."

The report also reveals, for the first time publicly, some other fundamental MAX design shortcomings. Investigators laid out the results of ground-simulator tests they conducted that pinpointed the difficulty of pilots cranking a control wheel in an emergency to counteract automated MCAS commands.

Particularly at higher simulated speeds and altitudes, according to the report, those manual actions to raise the nose required pilots to exert forces that were "very high and unbearable" for the required time periods. Some emergencies required dozens of turns of the wheel, the report indicates, while in others pilots couldn't budge the control wheel at all because of airflow forces pushing on flight-control surfaces.

After the Ethiopian crash and another MAX crash that occurred in Indonesia less than five months earlier, foreign regulators have criticized the FAA for failing to adequately flag such problems associated with manually moving an essential flight-control surface on the tail.

Regarding the role of Ethiopian Airlines, the report found the jet didn't have any technical problems prior to takeoff. But similar to findings in a preliminary report released by Ethiopia last year, the narrative spelled out the cacophony of warning sounds and lights, accompanied by a vibrating control column, that enveloped the pilots as they struggled to understand what was happening.

Write to Andy Pasztor at andy.pasztor@wsj.com

(END) Dow Jones Newswires

March 09, 2020 17:58 ET (21:58 GMT)

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