France’s Bureau d'Enquêtes et d'Analyses (BEA) on Tuesday followed the U.S. National Transportation Safety Board (NTSB) in calling for Ethiopian authorities to amend the final report on the March 10, 2019, crash of an Ethiopian Airlines Boeing 737 Max 8 to reflect human factors considerations and flight crew shortcomings. Ethiopia’s Aircraft Accident Investigation Bureau (EAIB) led the investigation with the help of the French and U.S. authorities, both of which said that the report failed to sufficiently address operational and crew performance in its finding that a malfunction in the airplane’s Maneuvering Characteristics Augmentation System (MCAS) caused the accident.
“Shortcomings relating to the crew’s actions, particularly in the first phase of the flight, is not accompanied by a thorough analysis of the reasons for the behaviors observed, in relation with their training, their experience and the company organization with regard to the training and knowledge acquisition principles,” said the BEA.
In summary, the BEA concluded that the crew’s inadequate actions and insufficient cockpit resource management played a role in the chain of events that led to the accident, in particular before the first MCAS activation.
The French authority has called for the EIAB to add five contributing factors related to the crew’s actions in the report, including the flight crew’s failure to apply the Approach to Stall or Stall Recovery Maneuver and the Airspeed Unreliable Non-Normal Checklist immediately after takeoff and before the first MCAS activation and the captain’s insistence on engaging the autopilot, contrary to the Approach to Stall or Stall Recovery maneuver procedure.
In its Tuesday statement, the French authority described how the crew did not fully follow the procedure for addressing the activation of the left stick shaker because of an erroneous angle-of-attack value, most likely caused by a bird strike.
“On the activation of the stick shaker, the flight crew must apply the Approach to Stall or Stall Recovery procedure, which is a memory item,” it said. “As described in the [Flight Crew Operating Manual/Quick Reference Handbook], the first steps in the Approach to Stall or Stall Recovery procedure are to hold the control column firmly, disengage the autopilot and autothrottle, and then smoothly apply a nose down input. Only the nose-down input was performed by the flight crew. The autothrottle remained engaged and the pilot later insisted on engaging the [autopilot].”
Other factors listed by the BEA include insufficient use of the electric trim to relieve the high control column forces after the MCAS nose-down orders and the captain’s lack of thrust reduction when the speed became excessive, which in combination with insufficient trim, caused an increase of the forces that became unmanageable on both the control column and the manual trim wheel.
Finally, the BEA faulted the airline’s use of the Logipad electronic flight bag system as the sole means to disseminate information related to the MCAS issued following the previous accident of a 737 Max—that of a Lion Air airplane on October 29, 2018. Because the Logipad system doesn’t allow the evaluation of the crew's understanding and knowledge acquisition on new systems and procedures, the airline could not ensure that the crew had read and correctly understood the information.