MCAS pushes the plane's nose down if it believes it is ascending at too steep an angle. "After the crash it came to our attention that the system is aggressive," Yohannes Hailemariam, vice president for flight operations at Ethiopian, told local reporters speaking in the Amharic language. "All pilots and operators knew about MCAS after Boeing disclosed that," he said. "When Boeing supplies aircraft there are items which are mandatory for safety and then there are optional items," he said. "The angle of attack indicator was on the optional list along with the inflight entertainment system.

Source: Ethiopian News March 24, 2019 15:00 UTC