WASHINGTON — The U.S. Energy Department's inspector general has cleared Energy Secretary Rick Perry of any wrongdoing in spending tens of thousands of dollars in taxpayer money on noncommercial air travel for him and his staff.

A report released Friday found that the former Texas governor and his aides were justified in using that kind of travel due to "exceptional scheduling requirements."

"Nothing came to our attention to indicate that non-career federal employees within the department had inappropriately taken trips on government aircraft," the report said.

Costly airfare tabs have dogged some key members of President Donald Trump's Cabinet, with former Health and Human Services Secretary Tom Price, Environmental Protection Agency administrator Scott Pruitt and Interior Secretary Ryan Zinke bearing the bulk of the criticism.

But Perry didn't avoid scrutiny, particularly after lawmakers in October pressed him on the handful of times he and his staff used government planes rather than commercial airlines.

"I continue to be concerned by the amount of money this administration is spending when it comes to noncommercial travel for members of the cabinet and their staff," Rep. Frank Pallone, a New Jersey Democrat, said at the time.

.@SecretaryPerry: "I travel a lot to do my job. I do it in a way that I think is thoughtful with the taxpayers in mind." pic.twitter.com/0v1eOskB3H — CSPAN (@cspan) October 12, 2017

The Texan defended the expenditures in part by blaming the World War II-era Manhattan Project for locating his agency's sites in hard-to-reach places across the U.S. He explained that it can be hard to get to a far-flung place like Hanford, Wash., in a "timely fashion."

"I travel a lot to do my job," he told lawmakers last year. "I do it in a way I think is thoughtful, with the taxpayers in mind. I'm going to continue to do my job. I'm going to try to do it in the most thoughtful and most reasonable way."

The Energy Department's inspector general report backed him up.

"The department has always believed that there has been no misuse of government aircraft by Secretary Perry and DOE staff," agency spokeswoman Shaylyn Hynes said on Friday.

The watchdog's report looked at noncommercial travel by top agency officials under Perry and under the last year or so of his predecessor, Ernest Moniz, to see if anything had changed since the Trump administration took over.

There were four such trips, including one outside of the country, in the latter years of the Moniz era. Those flights totaled more than $85,000. There have been five such trips, including one outside of the country, under Perry's management. Those flights totaled more than $93,000.

The inspector general said that while the trips were OK, the vetting process for them could benefit from more rigor in showing that more cost-effective commercial travel wouldn't suffice and from more "formal policies and procedures for justifying" the use of government planes.

But the office said it looked back at schedules and itineraries for the trips in question and found that "it would have been difficult for commercial airline service to accommodate the schedules."