Boeing didn’t tell FAA, airlines that cockpit alert wasn’t working

CHICAGO: Boeing Co knew months before a deadly 737 Max crash that a cockpit alert wasn’t working the way the company had told buyers of the single-aisle jetliner. But the planemaker didn’t share its findings with airlines or the Federal Aviation Administration until after a Lion Air plane went down off the coast of Indonesia in October, according to a Boeing statement on Sunday as it provided additional details of an issue that first came to light last week. The accident occurred after erroneous readings by a single angle-of-attack sensor triggered software that pushed the jet’s nose down until pilots lost control.

Boeing’s latest disclosure raises new questions about the 737 Max’s development and testing — and the company’s lack of transparency. The alert was supposed to flash when two angle-of-attack vanes sent conflicting data about the relation of the plane’s nose to the oncoming air stream. Boeing had told airlines and pilots that the so-called AOA disagree warning was standard across the Max fleet, as on a previous generation of 737 jets.

The software delivered to Boeing linked the signal with a second cockpit gauge — available for a fee —that displayed the readings from the two vanes. As a result, the AOA disagree light, which warned pilots of issues with the sensors, functioned only for customers that purchased the optional indicator.


“The question I have is just like we asked them in Reno, ‘Is that all there is?’ That’s the biggest question,” said Jon Weaks, head of the Southwest Airlines Pilots Association, referring to a meeting union leaders had with Boeing after the Lion Air crash. “It's obviously troubling that here is something else Boeing didn't get to us.”

The inactive alert was later deemed to be “low risk” by the FAA’s Corrective Action Review Board, the regulator said on Sunday. “However, Boeing’s timely or earlier communication with the operators would have helped to reduce or eliminate possible confusion,” the FAA said.

Boeing engineers discovered the discrepancy “within several months” of the initial Max deliveries in May 2017, the company said. The disclosures followed criticism from airlines and crash victims’ relatives that Boeing hasn’t been forthcoming about issues with the 737 Max, which has been grounded since a second crash in March, in Ethiopia.

The two disasters killed 346 people.