Once seen as a luxury of the corporate world, private planes are becoming increasingly common at U.S. colleges and universities as schools try to attract athletes, raise money and reward coaches with jet-set vacations.

Some schools spend millions of dollars a year flying their coaches and executives on scores of trips around the country, and some pass the cost on to students and taxpayers.

The Associated Press requested documents from dozens of public universities and found that at least 20 own or share ownership of planes for school business, often employing a few full-time pilots to fly them. Many others charter private flights through outside companies.

Flight logs show that, at times, the aircraft are used for purposes unrelated to university business.

At Ohio State University, which leases one plane and partly owns another, football coach Urban Meyer and members of his family took 11 personal trips last school year, including a vacation in Florida, a weekend getaway to Cape Cod and a spring break in South Carolina. The university’s cost: $120,000. Add Meyer’s 15 recruiting trips in the same planes during that period, and the price tag jumps to more than $350,000.

Meyer declined to comment.

Some private colleges, which aren’t subject to open-records laws, also own planes.

Colleges defend the costs, saying coaches and top administrators need to travel more than ever, while commercial airlines are offering fewer flights. Some say it’s economical for officials who often fly on short notice or to towns that are far from a major airport.

But some critics condemn such spending as a luxury at a time when tuition continues to rise.

“The students are paying for it or the taxpayers are paying for it, and it’s usually the students,” said Richard Vedder, an economist and director of the Center for College Affordability and Productivity in Washington, D.C.

Universities often use planes for athletic recruiting, mostly football and basketball, and to shuttle administrators on trips to woo donors or lobby lawmakers.