Veteran top engineer of the Boeing 777X and 737 MAX programs, executive Michael Teal is set to retire, according to a company memo seen by Reuters on Friday.

Teal, a 35-year Boeing veteran, held various engineering leadership roles, including vice president and chief project engineer on the 777X, 747-8 Freighter and 737 programs. His long-planned retirement date is April 1, the memo said.

Teal was a vice president and chief project engineer during the development of the 737 MAX, signing off on the jet's technical configuration. The plane was grounded worldwide after two fatal crashes.

David Loffing, who has held engineering roles on several programs, including the 747, NMA and 737, has been named as vice president and 777X chief project engineer, the memo said.

The 777X program has been hobbled for years by certification problems and weak demand for long-haul jets.

The United States and Europe approved the return of the 737 MAX in late 2020 and early 2021. The 737 MAX also regained airworthiness in China in December last year.

Teal was among the Boeing executives who testified before U.S. Congress during an investigation into the flawed Maneuvering Characteristics Augmentation System (MCAS) flight control system linked to the 737 MAX crashes.

Teal and Keith Leverkuhn, the vice president in charge of the overall 737 MAX development program, defended the jet's development and acknowledged flawed assumptions on how the pilots would react to the problems they encountered during the crash flights.

Teal also told investigators from the U.S. House transportation committee that he was unaware MCAS could activate repeatedly.

Boeing said later that Teal and Leverkuhn, who has retired, supervised hundreds of engineers and could not have been involved in every design decision.

(With input from Reuters)