While it was designing its newest jet, decided to quadruple the power of an automated system that could push down the plane’s nose — a movement that made it difficult for the pilots on two doomed flights to regain control. The company also expanded the use of the software to activate in more situations, as it did erroneously in the two deadly crashes involving the plane, the 737 Max, in recent months.
None of those changes to the anti-stall system, known as MCAS, were fully examined by the . Although officials were aware of the changes, the modifications didn’t require a new safety review, according to three people with knowledge of the process. It wasn’t necessary under FAA rules since the changes didn’t affect what the agency considers an especially critical or risky phase of flight.
by the FAA exposes an embedded weakness in the approval process, providing new information about the failings that most likely contributed to the crashes in and .
The FAA defended its certification process, saying it has consistently produced safe aircraft. An FAA spokesman said: “The change to MCAS didn’t trigger an additional safety assessment because it did not affect the most critical phase of flight, considered to be higher cruise speeds,”
A spokesman for Boeing said, “The FAA considered the final configuration and operating parameters of MCAS during Max certification, and concluded that it met all certification and regulatory requirements.”