Outside Activities

Professor Barsky went to Jakarta where he had a meeting with the head of the Aviation Accident Investigation Sub Committee of the Komite Nasional Keselamatan Transportasi (KNKT) (National Transportation Safety Committee) of Indonesia. They discussed the details the Lion Air JT610 crash of the Boeing 737 MAX on 29 October 2018. There were nine causes identified as having contributed to this tragedy:

1. During the design and certification of the Boeing 737-8 (MAX), assumptions were made about pilot response to malfunctions which, even though consistent with current industry guidelines, turned out to be incorrect.

2. Based on the incorrect assumptions about pilot response and an incomplete review of associated multiple flight deck effects, MCAS’s reliance on a single sensor was deemed appropriate and met all certification requirements.

3. MCAS was designed to rely on a single AOA sensor, making it vulnerable to erroneous input from that sensor.

4. The absence of guidance on MCAS or more detailed use of trim in the flight manuals and in pilot training, made it more difficult for flight crews to properly respond to uncommanded MCAS.

5. The AOA DISAGREE alert was not correctly enabled during Boeing 737-8 (MAX) development. As a result, it did not appear during flight with the mis-calibrated AOA sensor, could not be documented by the flight crew and was therefore not available to help maintenance identify the mis-calibrated AOA sensor.

6. The replacement AOA sensor that was installed on the accident aircraft had been mis-calibrated during an earlier repair. This mis-calibration was not detected during the repair.

7. The investigation could not determine that the installation test of the AOA sensor was performed properly. The mis-calibration was not detected.

8. Lack of documentation in the aircraft flight and maintenance log about the continuous stick shaker and use of the Runaway Stabilizer NNC meant that information was not available to the maintenance crew in Jakarta nor was it available to the accident crew, making it more difficult for each to take the appropriate actions.

9. The multiple alerts, repetitive MCAS activations, and distractions related to numerous ATC communications were not able to be effectively managed. This was caused by the difficulty of the situation and performance in manual handling, NNC execution, and flight crew communication, leading to ineffective CRM application and workload management. These performances had previously been identified during training and reappeared during the accident flight.