Patrick Shanahan, a former Boeing executive with no other government experience, is now the nation’s longest-serving acting secretary of defense in history, having taken on the role after James Mattis resigned in December. Some believed that Shanahan’s “acting” prefix would soon give way to a formal appointment to the job, but that effort has been delayed by an investigation launched by the Pentagon’s Office of Inspector General spurred by allegations of favoritism for Shanahan’s previous employer.

The investigation was prompted by a formal complaint filed by the Citizens for Responsibility and Ethics in Washington (CREW), a Washington D.C.-based watchdog group that asserts Shanahan has used his position to promote Boeing within the Department of Defense (DOD), seemingly to the detriment of Boeing’s competitor and F-35 manufacturer, Lockheed Martin. This alleged bias, according to CREW, has manifested in a number of ways, including the Pentagon pressuring the Air Force to procure new F-15 airframes from Boeing.

The CREW complaint states:

Mr. Shanahan worked for Boeing for more than 30 years before joining DOD in 2017. In private remarks he made since then at DOD, Mr. Shanahan reportedly praised Boeing in discussions about government contracts, said that Boeing would have done much better than its competitor Lockheed Martin had it been awarded a fighter jet contract, and repeatedly “dumped on” the jet Lockheed produced. News reports also asserted Mr. Shanahan prodded DOD to include funding for more Boeing-produced fighter jets in next year’s budget. His conduct and comments reportedly were perceived by DOD employees as ‘boosting’ Boeing.