Boeing Co. President Dennis Muilenburg testifies before House lawmakers Wednesday, the day after being peppered with tough question in the Senate during his first appearance before lawmakers since a pair of the planemaker’s 737 Max jets crashed, killing 346 people.
In both fatal crashes, faulty data from one of two angle-of-attack sensors, which measure the pitch of the plane against the oncoming stream of air, caused a flight control system called MCAS to drive down the jet’s nose, which pilots struggled to counteract before ultimately entering a fatal dive.
Here are the key developments:
CEO Acknowledges 737 Design Shortcomings (11:30 a.m.)
Muilenburg offered his most candid public assessment of the company’s shortcomings in designing a system implicated in two 737 Max crashes, after insisting for months that engineers followed the manufacturer’s and Federal Aviation Administration processes.
He said the company erred when it made a cockpit alert to inform pilots of disagreements between the 737 Max’s two angle-of-attack sensors available on only some of the jets instead of all, saying “we got that wrong up front.”
He also cited the original architecture of MCAS, which the company redesigned to incorporate readings from both angle-of-attack sensors instead of one on the original design. Thirdly, he said the company needs to improve communication and documentation.
But Muilenburg declined to name specific employees at Boeing or its 900-company supply chain who contributed to the botched design. “Mr. Chairman, my company and company alone is responsible,” he said. “I am accountable and my company is accountable.”
“We can and must do better,” Muilenburg said.
Lawmaker Confronts CEO With Internal Documents (10:53 a.m.)
DeFazio displayed slides of internal Boeing documents and emails—some never before seen publicly—raising questions about the development of MCAS, the flight control system linked to both crashes.
In both fatal crashes, faulty data from one of two angle-of-attack sensors, which measure the pitch of the plane against the oncoming stream of air, caused the MCAS to drive down the jet’s nose, which pilots struggled to counteract before ultimately entering a fatal dive.
In one document from 2015 a Boeing employee questioned the decision to permit MCAS to be triggered by only one of the two sensors mounted on the jet’s nose. Boeing has since redesigned MCAS to prevent a repeat of such a failure, in part by incorporating readings from both angle-of-attack sensors.
“I guess the question is, why wasn’t it that way from day one?” DeFazio said.
Another document from 2018 examined Boeing’s assumptions about how quickly pilots would respond to an MCAS malfunction.
Muilenburg concedes Boeing made three mistakes on MCAS: designing it to activate with a single sensor, omitting it from pilot training and under-estimating how long pilots would take to respond when the system kicked on.
“We made some mistakes. We discovered some things we didn’t do right. We own that. We are responsible for our planes,” Muilenburg said. “If we knew then what we know now we would have done it differently.”
Day Two Opens with CEO Response to New Allegations (10:03 a.m.)
As he was arriving for the hearing, Muilenburg told reporters that the safety concerns that prompted a manager to urge the company to pause the 737 Max assembly line were unrelated to the two fatal crashes by the jet.
The issue was related to “concerns about production line safety as we were moving to production rate changes,” Muilenburg said.
The comment came in response to assertions made Tuesday by DeFazio that a Boeing manager urged a superior to halt the 737 Max assembly line over safety concerns, one of a number of new allegations stemming from an investigation began by the panel days after the second 737 Max crash last March.
“We now know of at least one case where a Boeing manager implored the then-vice president and general manager of the 737 program to shut down the 737 Max production line because of safety concerns, several months before the Lion Air crash in October 2018,” DeFazio wrote in prepared remarks for the hearing.
