FILE PHOTO: Two Boeing 737 MAX 8 aircraft are parked at a Boeing production facility in Renton, Washington, U.S., March 11, 2019. REUTERS/David Ryder

WASHINGTON (Reuters) - A former Boeing executive who is now the Acting Secretary of Defense, Patrick Shanahan, told the U.S. Congress he has not spoken to anyone in the U.S. administration about issues with the 737 MAX 8 jet grounded Wednesday by the Federal Aviation Administration following crashes.

“I firmly believe we should let the regulators investigate the incidents,” the acting Pentagon chief told Senators at a hearing on Capitol Hill.

The United States grounded Boeing Co’s money-spinning 737 MAX aircraft on Wednesday over safety fears after an Ethiopian Airlines plane crash that killed 157 people, leaving the world’s largest planemaker facing its worst crisis in years.