We are concerned and sad for the fate of the 346 lives lost in these two MAX 8 crashes while their crew in their desperate fight had no idea of what kind of invisible demon got control of their flights and send them repeatedly and relentlessly towards the ground! We are awaiting anxiously the French BEA report. We are “humble and leaning” and this is why as a professional of the sector we have few questions for the community: Is the system at question part of the automatic flight control system (ATA 27) leading to stringent SDAL Level A development requirements? Yes / No Does this kind of System required to be fail safe (meaning their failure should not change dramatically the current path of the aircraft)? Yes / No Does the Master Minimum Equipment List (MMEL) deny to operate with one Angle Of Attack (AOA) Sensor failed? Yes / No Does the Configuration Deviation List (CDL) deny operation with one AOA down and sending misleading information to the rest of the Systems? Yes / No Could a Safety feature indicating discrepancy between sensors entering into a critical chain of failure that may lead to total loss of the aircraft be optional? Yes / No Could a Single Failure lead to the total loss of an aircraft or part of its crew or passengers? Yes / No Could a system be given total authority when OEM culture is to always keep pilots fully into the loop? Yes / No Does Aircraft Functional Hazard Assessment (FHA) or Operational Hazard Assessment (OHA) include the following feared event: loss or partial loss of longitudinal control? Yes / No Did the Pilots knew why the new system was installed (make sure that in extremely remote situations of high angle of attack and low speed, ie stall conditions, the use of power first to recover the situation, may worsen it with this specific aircraft type certificate? Yes / No Were the Pilots enough trained and aware of how the new system operates using the jack screw and noticeable in the cockpit through the visible and noisy Trim Wheel movements? Yes / No And finally would the system as designed pass the Citroen Law (What if I remove it all)? Yes / No ANY “NO” to my humble point of view would raise even more questions. Humbled and Learning as the President says and always stay with the mind set of continuous learner of the key requirements of a World Class OEM as from the quality of our work may depend the fate of the flying public and the stake could not be higher. Abdoulaye NDIAYE Aviation Expert
From Charybde to Scylla – How trying to fix a remote problem may lead to a bigger one.
Publication Date: April 1, 2019