A state audit is questioning Iowa State University’s purchase of a plane that was used often by former ISU president Steven Leath.

Iowa State paid about half a million dollars for the plane. Donations to the university were used to buy it. Auditors found the plane was used for 52 training flights to help the former ISU president earn an instrument rating. It means Leath got licensed to fly solo at all hours and in all conditions.

The auditor’s report said there was “limited use” of the plane for “clear business purposes” and suggested Leath should repay the university for a trip to his home in North Carolina. ISU officials say Leath did get a “benefit” from that spring break trip, but they say the trip was primarily a training flight for another pilot.

ISU sold the plane earlier this year, but the university is pushing back on the idea that buying it was a mistake. ISU officials say the plane helped Leath make fundraising calls.

Leath resigned as ISU president in March to become president of Auburn University. Iowa State sold the plane a couple of months later.