REPORT | Lion Air Boeing 737 MAX 8 Was Unfit to Fly

Photo: Reuters

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Indonesia’s National Transportation Safety Committee (NTSC) has released a preliminary report into the crash of Lion Air Boeing 737 MAX 8. It is confirmed that the aircraft which crashed into the Java Sea killing 189 on board was not in an airworthy condition the day before its fatal flight.

Previous Flight Data (28 October, 2018)

  • The Aircraft Flight Maintenance Log (AFML) recorded that since 26 October 2018 until the occurrence date several problems occurred related to airspeed and altitude flag appeared on Captain (left) Primary Flight Display (PFD) three times, SPEED TRIM FAIL light illumination and MACH TRIM FAIL light illumination two times and IAS (Indicated Airspeed) and ALT (Altitude) Disagree shown on the flight Denpasar to Jakarta the day before the accident flight.
  • On 28 October 2018, the accident aircraft was operated as a passenger flight from I Gusti Ngurah Rai International Airport (WADD), Denpasar11 to Jakarta as LNI043. The aircraft departed from Denpasar with two pilots, five flight attendants and 182 passengers.
  • During preflight check, the PIC discussed with the engineer the maintenance that had been performed on the aircraft. The engineer informed to the PIC that the AoA sensor had been replaced and tested accordingly. The PIC was convinced by the explanation from the engineer and the statement on the Aircraft Flight Maintenance Log (AFML) that the problem had been resolved.
  • However, the flight crew faced issues with an aircraft control. PIC had turned off the automatic safety feature, known as the maneuvering characteristics augmentation system (MCAS) and took manual control of the plane. The aircraft performed safe landing.
  • After parking, the PIC informed the engineer about the aircraft problem and entered IAS (Indicated Air Speed) and ALT (altitude) Disagree and FEEL DIFF PRESS (Feel Differential Pressure) light problem on the Aircraft Flight Maintenance Log (AFML).
  • The engineer performed flushing the left Pitot Air Data Module (ADM) and static ADM to rectify the IAS and ALT disagree followed by operation test on ground and found satisfied. The Feel Differential Pressure was rectified by performed cleaned electrical connector plug of elevator feel computer. The test on ground found the problem had been solved.

Additional Findings

  • According to the report released by the investigation team, the recovered wreckage identified consisted of, but not limited to, the left and right engines, both main landing gears, parts of the empennage, parts of the forward and aft left passenger doors, parts of the wings, a flight crew oxygen bottle, and parts of a circuit breaker panel. The damage to the aircraft suggested a high energy impact.
  • The CVR has not been recovered and search for the CVR is continuing. After finding the device, investigation is expected to find out why pilots of the fatal flight did not act the same as the pilots operating this aircraft the day before.