Boeing Chief Executive Officer Dennis Muilenburg says the company should have been more transparent with regulators and the public when Boeing discovered a safety light was not operating as designed.
Muilenburg made the comments to reporters ahead of the Paris Air Show, Boeing spokesman Gordon Johndroe told NPR.
"We clearly fell short in the implementation of the AOA disagree alert and we clearly should have communicated better with our regulators and the airlines," Johndroe said in an interview by phone from Paris.
Boeing's 737 Max plane has been grounded worldwide since the second of two crashes that together killed 346 people. In both the Lion Air flight in October 2018 and the Ethiopian Airlines flight in March 2019, pilots struggled to overcome a software program known as MCAS that drove the noses of the planes down. Now Boeing is working on a software update that will enable pilots to more easily control their aircraft.
The fatal crashes and the ongoing grounding of its fastest-selling plane have cast a shadow over Boeing's appearance at the Paris Air Show, which runs June 17-23.
"The company's presence and activities at the show will demonstrate its commitment to innovation, industry partnerships and safety," Boeing announced.
Both American Airlines and Southwest Airlines have extended 737 Max flight cancellations through early September. Previously, both airlines had planned to resume flights in August. American says about 115 flights will be canceled daily, and Southwest says about 100 flights will be removed from its daily schedule.
In his comments, Muilenburg referred to a safety feature connected to the sensors that feed into the MCAS software. The software would trigger when the plane was flying at an angle that might make a stall likely. Boeing designed a warning light to alert pilots when the two "angle of attack" sensors disagreed, which could mean MCAS would be triggered incorrectly.
The light was supposed to be standard on all versions of the MAX; however, in practice, it only worked on planes with other safety features that airlines bought for extra cost.
NPR's Laurel Wamsley has reported that Boeing knew the AOA disagree alert malfunctioned before the Lion Air crash.
Muilenburg conceded that engineers learned in 2017 that the alert light did not work as intended, and he said he was "disappointed" Boeing did not work to make the information more public, The Wall Street Journal reports.
Federal Aviation Administration spokesman Lynn Lunsford told NPR his office is working with Boeing throughout the testing of the software enhancement.
"We have not set a date for the certification flight," Lunsford wrote in an email.
Aviation expert Richard Aboulafia of the Teal Group said Muilenburg's comments appeared to reflect a change in tone.
"It's been a trade-off. Do you limit the short-term damage from liability cases, or do you focus instead on protecting the long-term brand equity of product and company, and they've been favoring the first option," he said. "That to me is a big mistake which seems to be changing."
Speaking from Paris, Aboulafia told NPR Muilenburg's comments had captured the attention of air show attendees.
"Standing around in cocktail parties, I think that is something people are remarking on," he said.