Conner said parent Boeing Co saw no reason to adjust its forecast for the number of 787 jets delivered this year. He spoke at an investor conference hosted by JPMorgan in New York.

The 787 was grounded worldwide in January after batteries burned on jets owned by All Nippon Airways Co Ltd and Japan Airlines Co Ltd. Boeing proposed a fix to the system on Feb. 22.

In response to a question by analyst Joe Nadol, Conner said "no question" that most of the mistakes with 787 were made early on in the program.