Ari Blaff writes for National Review Online about another piece of bad news for the U.S. transportation secretary.

The Department of Transportation (DOT) announced on Monday afternoon that it will be conducting an audit of Secretary Pete Buttigieg’s use of private jets.

The agency’s Office of the Inspector General noted that the investigation into Buttigieg will seek “to determine whether the Office of the Secretary complied with Federal regulations, policies, and procedures regarding executive travel on DOT aircraft.”

Buttiegieg responded on Twitter, noting he was “glad this will be reviewed independently so misleading narratives can be put to rest.”

“Bottom line: I mostly fly on commercial flights, in economy class. And when I do use our agency’s aircraft, it’s usually a situation where doing so saves taxpayer money.”

The Americans for Public Trust (APT), a government-watchdog organization that first obtained Buttigieg’s personal travel calendar, applauded the move as a big win for greater financial accountability.

“Everyday Americans have faced unprecedented flight cancelations and disruptions, but Buttigieg has continued to fly private, even on a Coast Guard plane and even when commercial options were readily available,” APT executive Caitlin Sutherland told Fox News Digital.

Reports by Fox News Digital showing that Secretary Buttigieg had used at least 18 Federal Aviation Administration (FAA) jets during his tenure prompted Senator Marco Rubio (R., Fla.) to file a request with the DOT inspector general.

“Senator Marco Rubio requested that we determine whether the Secretary’s use of Government aircraft for domestic and international travel complied with all applicable Federal regulations and DOT policies and procedures,” the federal agency’s statement said. “Accordingly, we will conduct an audit to determine whether the Office of the Secretary complied with Federal regulations, policies, and procedures regarding executive travel on DOT aircraft.”

The cost of those 18 flights, along with accompanying staff, according to a recent Washington Post story, amounted to just over $40,000.