A U.S. Dept. of Transportation investigator reported that both Boeing Co. and the Federal Aviation Administration were responsible for mistakes in the certification process for the Boeing 737 MAX aircraft, which entered commercial service in 2017 and then was involved in two fatal crashes, in 2018 and 2019.
Importantly, the Inspector General's report concludes that Boeing failed to report to FAA " the scope and potential safety impacts" of changes it introduced to the 737 MAX Maneuvering Characteristics Augmentation System (MCAS), the flight-control program that has been identified as the cause of the two crashes.
Neither Boeing nor the FAA has commented on the contents of the IG report. In the weeks ahead, the Dept. of Transportation Inspector General office is expected to issue recommendations to FAA about the conclusions of the inquiry.
The 737 MAX is a twin-engine, narrow-body aircraft that Boeing that has been idled worldwide since March 2019. A total of 346 passengers and crew members were killed in those events, in October 2018 and March 2019.
A new MCAS has been developed and is undergoing certification flights this week, conducted by Boeing and FAA pilots.
The 737 MAX was conceived as a new version of the 50-year-old 737 series, but a Boeing whistleblower has contended that the OEM sought to expedite the certification process and so downplayed to FAA the extent of the aircraft redesign. According to the Inspector General's report, The MCAS was "not an area of emphasis" for FAA because Boeing presented it as a modification of the previous model jet's speed trim system.
Notably, the IG's report also implicated the FAA in the mishandling of the aircraft certification.
“Boeing did not submit certification documents to FAA detailing the change,” according to the IG report. “FAA flight test personnel were aware of this change, but key FAA certification engineers and personnel responsible for approving the level of airline pilot training told us they were unaware of the revision to MCAS.”
In January 2019 — following the crash of a Lion Air 737 MAX but before the crash of the Ethiopian Airlines jet — the FAA conducted its first detailed review of the MCAS system. That review resulted in documentation, but that report never finalized, according to the IG.
Also in that period between the two crashes, the FAA conducted a risk analysis of the 737 MAX and found that the aircraft carried a risk of 2.68 fatalities per 1 million flight hours, more than twice the agency's risk guidelines of 1 fatality per 10 million flight hours.
A December 2018 FAA analysis concluded there was a risk of about 15 accidents for the full service life of the entire 737 MAX fleet if the MCAS software was not corrected and adopted.
Boeing proposed the MCAS redesign before the second crash, and FAA accepted that proposal. That redesign was to have been completed and installed by April 12, 2019. The second 737 MAX crash happened on March 10, 2019.
During the 15 months since the grounding of the 737 MAX fleet, other wiring corrections also have been identified and are being proposed.
