Boeing’s response to its rival’s move was a more efficient engine, but the Max engine was bigger than the earlier versions. To address this engineering challenge, Boeing updated the software for the flight control system. After the Lion Air crash, some American aviation authorities said that the change had not been adequately explained to pilots. Whether Ethiopian Airlines, which, unlike Lion Air, has a strong safety reputation, carried out that training was not immediately known. And what is known so far does not rule out pilot error or the malfunction of a completely separate system.

Source: New York Times March 10, 2019 23:02 UTC