Cockpit Voice Recorder from Lion Air Flight 610 Crash Found
Aviation safety officials in Indonesia announced on Monday that divers in the Java Sea retrieved the cockpit voice recorder from Lion Air Flight 610, a discovery that could indicate what pilots did before the crash on Oct. 29 when 189 people died.
The crash was the first fatal accident of the Boeing-built 737 MAX 8, the latest model of the 737-class airliner. If the background audio and voice recordings from the cockpit are intact, investigators could discover more about what happened during the 13 minutes between takeoff from Jakarta and the crash.
Indonesia’s National Transportation Safety Committee has studied the flight data recorder that was recovered from the sea on Nov. 1, which includes data from several flights during the days prior to the crash . Following the discovery of the cockpit voice recorder by Indonesia Navy divers, Boeing said in a statement the company “is working closely with the U.S. National Transportation Safety Board as a technical advisor to support Indonesia’s National Transportation Safety Committee.”
The two pilots each had thousands of flight hours of experience and the plane had only been in operation for two months, according to the preliminary report about the crash published in October by Indonesia’s National Transportation Safety Committee.
Conversations between the pilots could indicate how pilots responded to an automated anti-stall flight control system installed on the 737 MAX 8, says Mary Schiavo, an attorney and the transportation practice group head at Motley Rice law firm.
Pilots flying the 737 MAX 8 on Oct. 28, the day before the crash, had to respond to the Maneuvering Characteristics Augmentation System designed to automatically trim the plane’s nose downward to prevent it from stalling at a dangerously high angle, investigators reported. Faulty air speed and altitude information from an angle of attack pitot tube sensor on the side of the plane triggered that system, making it difficult for the pilots to adjust the flight angle and maintain altitude.
The pilots on Oct. 28 turned off the anti-stall system and completed the flight as planned on manual controls. The crew during the fatal flight on Oct. 29 faced similar trouble when erroneous data triggered the anti-stall system and radioed air traffic controllers reporting “flight control problems” prior to the crash.
The cockpit voice recorder could uncover what the Flight 610 pilots may have done differently than the previous flight crew during the moments before the crash, Schiavo says.
“I would anticipate there will be a lot more information in the final report about what was missed in maintenance because of faulty communications,” said Schiavo, who was inspector general of the U.S. Department of Transportation from 1990 to 1996. “Investigators will want to know from the cockpit voice recorder if the flight crew looked at the prior flight logs to figure out if there were issues before to try to decide how to trouble shoot. Probably not, they had no time. They were resorting to their checklists and manual and fighting with the plane. Were the manuals and training lacking in how to deal with this situation?”
Questions facing investigators include how lack of aircraft maintenance and lack of training factored into the crash. Investigators have not yet determined the cause of the crash but reported the plane should not have been cleared for flight the day after pilots had erroneous stall warning problems with the flight controls. Maintenance logs for the plane also recorded faulty airspeed readings during the four flights prior to the crash on Oct. 29.
Despite the crash, Boeing said in December the 737 MAX 8 “is the fastest-selling airplane in Boeing history,” and announced 181 new sales that month, surpassing 5,000 net orders for the plane worldwide. The company respondedin November to the crash investigation with a statement that the 737 MAX 8 is “as safe as any airplane that has ever flown.” Lion Air co-founder Rusdi Kirana told Bloomberg in December that he felt “betrayed” by responses about the crash from the planemaker and would propose to his company that they cancel orders for around $22 billion worth of Boeing planes that are scheduled for delivery.
“I’m one of their biggest buyers,” Kirana told Bloomberg. “They should have helped, not give a negative impression on us.”
Boeing created the Maneuvering Characteristics Augmentation System to prevent stalling on 737 MAX planes because they are the first Boeing planes to include Leap-1B engines built by CFM International. Those engines generate additional lift at a high angle of attack on 737 MAX planes because of their size and high placement on the wings.
The FAA published an emergency airworthiness directive in November, requiring U.S. owners and operators of 737-8 and 9 series planes to amend operating procedures to address how pilots should respond when the Maneuvering Characteristics Augmentation System erroneously trims a plane’s nose downward. Based on analysis completed by Boeing, the FAA said in the directive, “erroneously high single angle of attack sensor input” could trigger the flight controls to repeatedly trim the plane’s nose downward, make it difficult for pilots to control the plane and risk “possible impact with terrain.”