Boeing executives told lawmakers on Tuesday that they made mistakes developing the 737 Max plane, grounded worldwide after two crashes killed 346 people.
In a fiery hearing on Capitol Hill, Sen. Maria Cantwell, a Democrat from Washington, the state where the 737 Max is made, asked Boeing’s CEO Dennis Muilenburg and the commercial airplane unit’s chief engineer whether its safety assumptions and assessments were wrong.
“In hindsight, yes,” said chief engineer John Hamilton in a Senate Commerce Committee hearing. It is the first time Boeing executives are testifying before lawmakers on Capitol Hill.
At issue is a flight-control system known as MCAS that malfunctioned on both flights because it received erroneous data from a faulty sensor. The sensor measures the angle of attack, or the angle of the plane relative to oncoming air. If the nose is pointed too high, the plane could stall, so the system automatically pushes the nose of the planes down.
In the case of both crashes — Lion Air Flight 610 that went down in the Java Sea exactly one year ago today, and an Ethiopian Airlines crash in March — pilots battled the system that repeatedly pushed the nose of the planes down.
Hamilton said Boeing didn’t “specifically” test an unintended activation of the system because of an issue with an angle-of-attack sensor.
The FAA, last week, shut down the Florida maintenance facility that worked on one of the Lion Air sensors.
Boeing has been highly criticized for its assumptions about the plane, including overestimating average pilots’ ability to safely fly planes amid a flurry of cockpit alerts, which occurred on the Lion Air jet.
“We relied on these longstanding industry standards of pilot response,” said Muilenburg, adding that was an area where “we found shortfall.”
Boeing shares were up 0.5% in late-morning trading.