But the captain of the Max 8 that crashed this month in Ethiopia shortly after takeoff, killing all 157 people on board, never trained on the simulator, according to people close to the airline’s operations . Another Max 8 crashed five months ago in Indonesia in a similar way.

Background: Even after the crash in Indonesia, Boeing had said that pilots experienced with older models of the 737 did not need additional simulator training, and the U.S. Federal Aviation Administration agreed. That thinking is set to come under official scrutiny. Also, many pilots were not originally informed of the existence of an automated system suspected of playing a role in both crashes.

Top F.A.A. officials were not aware of the software system and special attention was not paid to it, according to people with knowledge of the safety certification process for the Max 8. The plane is now grounded worldwide as Boeing races to come up with a fix to the system, which can push the plane’s nose down if it approaches a stall.