Boeing Withheld Facts on Flight-Control System Blamed for 2 Fatal Crashes
Boeing may have provided only “limited information” on the flight-control software later implicated in two fatal crashes on the 737 Max as it was being approved by federal regulators, a government watchdog report has found.
The Transportation Department’s Inspector General concluded that changes to a system that automatically pushed down the plane’s nose weren’t fully communicated to Federal Aviation Administration officials, which led them to focus on other issues with the plane.
Boeing’s best-selling jet has been grounded since March 2019 after the second of two crashes that killed a total of 346 people. While some of the details released by the inspector general have been contained in other investigative reports or news articles, the latest report contains the most extensive timeline of the plane’s approval to date.
Boeing, in a statement, said it has cooperated with the investigation and made “robust improvements” to the flight control system. “We are committed to transparency with the FAA during all aspects of the airplane certification process, and have made significant changes to improve our support to that regulatory process,” the company said.
In a response included in the report, the FAA acknowledged that its certification of the jet was hampered by a lack of effective communication with Boeing and within the agency. This led to “an incomplete understanding of the scope and potential safety impacts” of the changes to the system that helped led to the crashes.
The report revolves around the approvals for the Maneuvering Characteristics Augmentation System. It was added to the plane to nudge the nose down in certain high-risk conditions so that the aircraft complied with federal regulations.
However, in both crashes — one off the coast of Indonesia in October 2018 and the second near Addis Ababa, Ethiopia, in March 2019 — a malfunction caused it to repeatedly attempt to dive the planes. Pilots in both cases lost control.
FAA engineers responsible for approving pilot training requirements were unaware of revisions to MCAS that occurred during the design, the agency said. “FAA’s certification process relies on receiving complete, candid information from manufacturers,” it said.
The agency is revising its oversight of the program that permitted designated employees of a manufacturer to perform certification work and will release details in coming months.
“This and other reviews, both completed and ongoing, will inform important reforms of FAA’s aircraft certification process,” the FAA response said.
The FAA is conducting certification test flights of the plane this week. MCAS was redesigned so that it won’t operate repeatedly and the post-crash reviews prompted several other revisions, including an extensive change to the plane’s flight-control computer.
The inspector general’s timeline lays out in detail how opportunities were missed to more closely assess MCAS.
Boeing officials mentioned the new flight control software during meetings in 2012 and 2013 with FAA officials as plans for the Max were taking shape. But MCAS wasn’t emphasized as the planemaker focused on the Max’s larger engines and other key differences from the previous generation of 737s.
Of 482 slides presented during a technical familiarization meeting in May 2012, only two lines of text mentioned MCAS, the report said. It was presented as a minor modification to an existing system that functioned only at higher speeds.
In 2016, however, Boeing determined that MCAS needed to function across a wide range of speeds and, as a result, gave it more power to push down the nose. It altered the system so it could move more than four times as much, the report said.
Even though the changes could have been seen as increasing the hazard potentially created by the system, Boeing assumed that it could be recognized by pilots within four seconds, giving them plenty of time to regain control.
Under that assumption, Boeing to labeled the system with a less critical safety rating, which allowed it to avoid more complex safety assessments.
“Despite these significant revisions,” the report said, Boeing didn’t note the changes to FAA’s certification engineers.
A short time later, the FAA approved removing references to MCAS from the jet’s pilot manuals and training materials. The FAA representative who approved the changes told investigators that he or she wasn’t told about the changes to the system.
The regulator wasn’t completely in the dark about MCAS. FAA flight-test workers knew that it had increased range, the report said.
“This varied understanding of the final flight control design of the 737 Max among different FAA offices demonstrates a lack of consistent and transparent communication both between Boeing and FAA, as well as within FAA,” the report said.
The report also raises questions about a system that had expanded in recent decades giving companies such as Boeing more authority to use their own employees to act as FAA deputies and sign off on designs.
Known as Organization Designation Authorization, the inspector general had found evidence of “undue pressure on ODA unit members, quality and timeliness of certification documentation, and the effectiveness of FAA oversight” at the same time that the Max was being certified. However, none of the issues related directly to work on the new plane, the report said.
After initially reserving the right to review MCAS itself, FAA late in the certification process delegated the final approval for MCAS back to Boeing.
Only after the Lion Air crash on Oct. 29, 2018, did the FAA’s certification engineers perform a detailed review of MCAS. For some, “it was also the first time they were presented with a full picture of how MCAS worked,” the report said.
Boeing was working toward an April 12, 2019, target to redesign the software under the FAA’s supervision when the second crash occurred.
The inspector general said it intended to delve into the certification process and would make recommendations, as applicable, in future reports.