Indonesian National Transportation Safety Committee, known as KNKT, released its final investigation report for the Lion Air flight 610 crash just days before the tragedy’s first anniversary. The findings confirm what has already been reported and echo findings by the U.S. National Transportation Safety Board (NTSB) that were published earlier this month.
The report notes that the flight crew, the airline’s maintenance work and a Florida firm that supplied Lion Air a secondhand component all contributed to the series of events that caused the crash. However, the bulk of the responsibility was attributed to the development and inadequate oversight by U.S. regulators during the certification of the Boeing 737 MAX’s MCAS, a new feature of the aircraft’s flight control system.
Shortly after takeoff, the MCAS erroneously activated due to inaccurate information the aircraft’s single Angle of Attack (AOA) sensor sent to the system. Pilots began a tug-of-war with the MCAS trying to regain control of the plane. Regardless of the pilots’ efforts to disengage the automated system and pull the nose of the plane back up to an appropriate altitude, the MCAS continued its “uncommanded activation” or kept autonomously reactivating until the plane crashed into the Java Sea, killing all 189 people on board.
Boeing developed the system to address aerodynamic problems created by the redesign of the 737’s latest iteration. It was designed to be hidden and separate from the autopilot system. Pilots were never made aware of the system, contributing to their difficulty in handling the challenges it created during the flight. Further, the safety assessment of the MCAS was conducted by Boeing and not the Federal Aviation Administration (FAA), which is charged with regulating aviation safety in the U.S. The agency endorsed a self-certifying safety certification by delegating the entire process to the plane’s maker. The report also slammed Boeing for basing much of its assessment on assumptions about pilots’ responses to uncommanded activations – assumptions it presented to the FAA and that were significantly deficient.
The report stated that “[t]he certification was done by Boeing…without properly considering the severity of the problem.”
The report also discussed the two safety features that weren’t available on the aircraft for flight 610 and may have helped the pilots maintain control of the aircraft. Although Boeing knew the 737 retrofit design suffered from aerodynamic problems that could cause the plane to stall, it chose to make vital safety equipment optional including an AOA indicator light and a “disagree light.”
The report provided a list of detailed recommendations, including a number of items specific to Boeing:
- Reliable and safe redesign of the MCAS.
- Consider the effect of all flight deck alerts and indications on flight crew recognition and response.
- Provide enough information about the MCAS in pilot manuals and training to minimize the potential for flight crew actions that are inconsistent with manufacturer assumptions.
- Include a larger tolerance in the design is required to allow operability by a larger population of flight-rated pilots.
- Closely scrutinize the development and certification process for systems whose malfunction can lead to loss of control of the airplane.
The report was prepared by KNKT, which received support and assistance from the NTSB and similar accident investigation and safety agencies of Australia, Singapore and Malaysia.
It comes as Boeing CEO Dennis Muilenburg prepares to testify before Congress next week. He and Boeing have maintained that the 737 MAX was FAA certified in accordance with all the appropriate regulations. Muilenburg also insisted in April, following the second 737 MAX deadly crash, that Boeing had not made any technical mistakes with its engineering or certification of the aircraft.
About Mike Andrews
Mike is a lawyer in the firm’s Personal Injury and Products Liability section. He has represented people seriously injured in aviation crashes, and the families of those killed in both civilian and military airplane crashes and helicopter crashes. He also has written a book on the subject to assist other aviation lawyers, “Aviation Litigation & Accident Investigation.” The book offers an overview to the practitioner about the complexities of aviation crash investigation and litigation.