It’s not the first time the Army has suspended Apache deliveries. From March to August 2018, the service halted acceptances after finding a flaw in a part that holds the helicopter’s rotors to the aircraft.

Boeing quality-control practices have been called into question by both the commercial industry and the military. The Federal Aviation Administration is investigating potential manufacturing issues on 787 Dreamliner aircraft.

The U.S. Air Force had to halt deliveries of KC-46 tankers on numerous occasions after military inspectors found trash, parts, and tools left inside the aircraft. In March 2019, Will Roper, the head of Air Force acquisition, blamed the company’s assembly line culture for the issues.

The coronavirus pandemic has only made things worse for Boeing and its suppliers as air travel evaporates and airlines cancel plane orders. Earlier this year, executives said the company’s $34 billion defense business would outperform its typically lucrative commercial business for the first time in more than a decade.