Boeing knew of Max software issue for a year before telling airlines, regulators

Boeing is facing new scrutiny over when it informed U.S. regulators and airlines of a software glitch with the beleaguered Boeing 737 Max jet, one the Chicago-based manufacturer first learned of months after deliveries began and a year before the first fatal crash involving the jet.

In 2017, Boeing discovered an error with the angle of attack (AOA) Disagree alert, which notifies pilots of discrepancies with the sensors that track the lift of a plane’s nose. The company reviewed the issue with “multiple company subject matter experts” and determined that it “did not adversely impact airplane safety or operation,” according to a statement released on Sunday.

The software linked the AOA disagree alert to a separate indicator, which was not standard and had to be purchased as an add-on feature, Boeing wrote.

“The software activated the AOA Disagree alert only if an airline opted for the AOA indicator," it said.

Senior Boeing leaders and the Federal Aviation Administration were not informed of the cockpit error until November 2018, after the Lion Air crash that left 189 people dead. A FAA review board found the issue to be “low risk,” the agency said in a statement. A fix was mandated as part of a software patch that Boeing began work on after the October incident.

Meanwhile, in some cases domestic carriers who purchased the Max did not learn of the software glitch until after the Ethiopian Airlines crash that left 157 people dead and led to an international grounding of the fleet, according to the Wall Street Journal and carriers. Southwest Airlines was informed in late November, while United Air Lines was told at the end of March.

“Boeing’s timely or earlier communication with the operators would have helped to reduce or eliminate possible confusion,” the FAA said.

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A Southwest spokesperson did not immediately respond to request for comment.

An American Airlines spokesperson said the carrier had both the AOA Disagree alert and indicator on all 737 jets since the first delivery in 1999.

In its statement, Boeing said all Max jets will have an “activated and operable” alert when the fleet returns to service. The company has yet to submit a software patch to the FAA for review.


The House Transportation Committee is reportedly investigating why the FAA and Boeing were not more forthcoming with public information on the issue with the sensor, according to the Journal. A panel spokeswoman did not immediately respond to a FOX Business inquiry.