The Ethiopian government issued interim report on Boeing 737MAX crash that killed 157 people.
The interim investigation report blamed Boeing’s design of the jet’s new flight control system and the training Boeing offered pilots.
The report states that the system known as MCAS — the Maneuvering Characteristics Augmentation System, designed to push the nose of the aircraft down in certain circumstances where it tended to pitch up — activated three times, initiating a struggle as the pilots on Flight 302 tried to pull the nose back up, before the pilots apparently switched it off.
The report notes Boeing had assumed that pilots would handle a system failure using a standard procedure that involved switching the system off and then using a manual wheel to swivel the horizontal tail so as to pull the nose back up.
However, the report concludes, the pilots found that manual trim wheel immovable, due to the high forces on the tail of the aircraft.