Boeing safety analysis of 737 Max flight control system had 'crucial' flaws
The FAA delegated most safety assessments to the plane maker itself and ordered its own engineers to quickly approve the resulting analysis, report says
Boeing’s safety analysis of the new flight control systems on its troubled 737 Max jets, which it submitted to the US aviation regulator, had several crucial flaws, according to the Seattle Times.
The US plane maker had understated the power of the flight control system, known as Maneuvering Characteristics Augmentation System, or MCAS, the newspaper reported.
The Seattle Times detailed a close relationship between Boeing and the Federal Aviation Administration during the certification process of the 737 Max, saying the regulator delegated much of its safety assessments to Boeing itself and ordered its engineers to quickly approve the resulting assessment.
Boeing’s analysis failed to account for how the system could reset itself each time a pilot responded – in essence repeatedly pushing the airplane’s nose downwards – present and former engineers directly involved, or familiar with the analysis, told the newspaper.
The report categorised a potential failure of the MCAS as "hazardous" – one level below "catastrophic". Such a ranking should have been enough to require reliance on more than one input sensor, the engineers told the daily.
Several FAA technical experts said as the certification proceeded, managers prodded them to speed the process as development of the Max was lagging nine months behind European rival Airbus’ A320 Neo.
Boeing and the FAA were informed of the investigation by the Seattle Times and were asked for comment 11 days ago, before the crash of an Ethiopian Airlines 737 Max jet last Sunday that killed all 157 people on board. The same model operated by Indonesia’s Lion Air plunged into the Java Sea in October, killing all 189 on board.
The FAA told the Seattle Times that it followed its standard certification process on the Max. Boeing said the FAA had reviewed the plane maker’s data on the plane and concluded that it “met all certification and regulatory requirements".
The US company, which builds its commercial jets in Seattle, said there are “some significant mischaracterisations” in the engineers’ comments about the flaws of the MCAS certification.
The Wall Street Journal separately reported that the US Department of Transport is investigating the FAA's approval of the 737 Max jetliners.
Citing people familiar with the inquiry, the WSJ said federal prosecutors and the transport department are scrutinising the development of the revamped jet.
A grand jury in Washington, DC, issued a broad subpoena dated March 11 to at least one person involved in the plane's development and sought documents to be handed over this month, the WSJ reported on March 17.
It was unclear whether the subpoena from the Department of Justice was related to the DoT's inquiry into the FAA's approval of the plane's MCAS system, the newspaper said.
Bloomberg also reported that the US transportation department’s inspector general was examining the plane’s design certification before the second of two deadly crashes involving the same 737 Max plane model, citing people familiar with the matter.
Boeing's share price dropped 2.4 per cent to $369 in New York at the start of trading on Monday, following reports of increased scrutiny by prosecutors and regulators on whether its jet approval process was flawed.
On Sunday, Ethiopia's transport minister Dagmawit Moges said that flight-data recorders showed "clear similarities" between Ethiopian Airlines flight 302 and the Lion Air plane crash in October that killed all 189 people onboard.
Boeing issued a statement in response, extending its sympathies to the victims' families.
"While investigators continue to work to establish definitive conclusions, Boeing is finalising its development of a previously-announced software update and pilot training revision that will address the MCAS flight control law's behavior in response to erroneous sensor inputs," Dennis Muilenburg, Boeing chief executive, said.
Updated: March 19, 2019 12:37 PM