Investigators from the US National Transportation Safety Board (NTSB) have published a report on the investigation of the Boeing 737 MAX crashes . They concluded that when designing the plane, the company incorrectly predicted the actions of pilots in special situations.
In developing and certifying the new MCAS, Boeing and the Federal Aviation Administration made incorrect assumptions about what pilots would look for in real-life flight, when they must monitor multiple cockpit readouts.
As a result, the NTSB recommended revising the certification program to include proper assessment of pilot performance under stress. The board also suggested developing updates to onboard operating systems to more accurately report malfunctions.