Investigators scouring black box data believe an automatic anti-stalling feature was engaged before a Boeing 737 MAX jet crashed and killed 157 people in Ethiopia.
The feature, known as MCAS, also was a factor in the October crash in Indonesia, according to investigators. The investigators said inaccurate information from an outside sensor led MCAS to force the nose of the plane down over and over again.
Pilots proved unable to regain control and prevent disaster, and the Lion Air flight eventually crashed in the Java Sea, killing 189 people.
Boeing on Wednesday detailed a software update it said will make MCAS more reliable and less powerful. They also said all MAX pilots would be required to get new training.