Boeing refuses to comment on a lawsuit filed Thursday by 17 relatives of people who died aboard the Lion Air 737 Max 8 that crashed into the Java Sea last October.
“Boeing extends our heartfelt condolences to the families and loved ones of those onboard Lion Air Flight 610,” the company said in a statement, adding that it is cooperating fully with investigators in Jakarta, Indonesia.
The suit, filed by aviation attorney Chuck Hermmann, blamed the crash of Lion Air Flight 610 on software new to the Max series of 737s. Called MCAS (Maneuvering Characteristics Augmentation System), the software was installed to counter flight control differences attributed to the new models’ bigger, heavier engines. Engineers designed the MCAS in part to push down the aircraft’s nose down in the event of a high-speed aerodynamic stall. However, Herrmann alleged Boeing never told pilots about the MCAS and included no mention of it in the 737 Max 8 flight manual.
For three days, crews flying the accident aircraft had reported problems with the angle of attack (AOA) sensor, complaining of repeated stick-shaker activations and of fighting the autopilot to keep it from forcing the airplane’s nose down.
Two minutes after takeoff from Jakarta on a flight to the Sumatran island of Bangka-Belitung, the crew aboard JT610 reported “flight control issues.” The MCAS had received faulty data from the AOA sensor, indicating the aircraft was in a nose-high stall, Herrmann said. The MCAS then tried to correct the problem by pushing down the nose.
The crew of JT610 fought the MCAS for approximately 12 minutes before the 737 Max 8 finally plunged more than 5,000, hitting the surface of the Java Sea at approximately 500 knots. All 189 people aboard died.
“[Boeing] didn’t inform the pilots even of the existence of MCAS, let alone provide instructions on how to respond if the MCAS failed,” Herrmann told AIN.
News about the existence of the system indeed appeared to catch other pilots by surprise.
"It is something we did not have before in any of our training. It wasn’t in our books,” said American Airlines 737 pilot Dennis Tajer, who also serves as the airline’s pilot union spokesman. Pilots of other airlines made similar statements. After the demise of JT 610, Boeing issued a pair of multi-operator messages in November, indicating that erroneous AOA data could cause the MCAS to push down the nose even when no correction was required. Boeing also took the highly unusual step of meeting with pilot unions to describe the software, the situation in which the MCAS might trigger an unwarranted pitch-down, and steps flight crews could take to disable it.
“Had they known about MCAS and had been properly trained about the procedures they could follow to disable it in the case of a malfunction, they could have pulled out of the fatal dive,” said Co-counsel Mark Lindquist, who has spent months in Jakarta talking with families of the victims. “But they didn’t know.”
Boeing Chairman and CEO Dennis Muilenburg has repeatedly said the 737 Max 8 is safe and denied that Boeing withheld operating details from flight crews. However, soon after the crash of JT 610, the FAA issued an Emergency Airworthiness Directive, AD 2018-23-5,1, containing instructions on how to disable the MCAS in instances where AOA data is corrupted or misinterpreted in a way that puts the aircraft into an uncommanded dive.