MCAS failure could have caused 15 more MAX crashes

By December 12, 2019 Uncategorized

On Wednesday the US House of Representatives Transportation Committee chairman Rep. Peter DeFazio requested FAA administrator Stephen Dickson to investigate why the agency did not ground the 737 MAX, when its own analysis performed after the October 2018 crash of Lion Air Flight 610, predicted as many as 15 more fatal accidents over the model’s service life if its flight control problem went uncorrected. Addressing the fifth transportation committee hearing on the MAX crashes, DeFazio noted that the FAA also reached the conclusion that 99 out of 100 flight crews could comply with the airworthiness directive and successfully react within ten seconds to the “cacophony” of alarms and alerts recounted in the Lion Air crash report.

“Such an assumption we know now was tragically wrong,” he said. “Despite its own calculations, the FAA rolled the dice on the safety of the travelling public and let the MAX continue to fly until Boeing could overhaul its MCAS software. Tragically, the FAA’s analysis, which never saw the light of day beyond the closed doors of the FAA and Boeing, was correct.”

After the crash of the Lion Air MAX, the FAA issued an emergency airworthiness directive giving pilots of Boeing 737 MAX 8 and MAX 9 variant procedures to follow in the event of a runway horizontal trim caused by faulty AoA inputs to the aircraft’s flight control system. The Air Directive (AD) came a day after Boeing issued an operations manual bulletin in response to investigators’ findings that the Lion Air 737 MAX 8 that crashed into the Java Sea on October 29, was due to erroneous input from one of the sensors. According to the AD, an analysis performed by Boeing showed the defect could lead to a repeated nose-down trim command of the horizontal stabiliser, so compromising the controllability of the aircraft and creating an excessive nose-down attitude. Although the AD required a revision to the chapters in the aircraft’s flight manual dedicated to certificate limitations and operating procedures for addressing a runaway stabiliser, it did not mention the system implicated in both the Lion Air and Ethiopian Airlines crashes by name.

“The FAA issued an emergency airworthiness directive that purported to inform pilots on how to respond to an erroneous activation of MCAS while actually never mentioning the system by name,” said DeFazio. “In fact, during the certification of the 737 MAX Boeing actively pushed the FAA to remove references to the MCAS from the flight crew operating manual, as revealed in the emails and instant messages from Boeing executive Mark Forkner.”

What has to be taken into account is that Dickson began his tenure at the FAA after the agency performed its analysis but, has expressed a desire to resolve the situation as quickly and as safely as possible for all parties.