LANSING — The state's practice of allowing its passenger planes be used by Michigan State University coaches and staff for athletic recruiting trips is the subject of a federal review, officials said.

The Federal Aviation Administration inquiry comes less than a month after the Lansing State Journal published a series on the taxpayer-funded planes that focused on how the aircraft are used and who uses them, the newspaper reported.

The FAA, the Michigan Department of Transportation and the school said a preliminary investigation is underway. MDOT and Michigan State University said the review relates to the East Lansing school's use of the state-owned planes by top athletic officials.

The review could trigger a formal FAA investigation.

MDOT spokesman Jeff Cranson said the FAA is seeking financial documents such as billing, invoices and proof of payments. The agency was contacted by the FAA last week, he said.

"MDOT aeronautics officials are happy to cooperate with the FAA," Cranson said. "The MDOT Office of Aeronautics treats MSU the same as they treat every other customer state agency."

MDOT is responsible for the state's four passenger planes and manages the flight schedule. The aircraft are available to state employees and those who work for Michigan's four-year public universities who can justify the travel costs for work purposes.

The Lansing State Journal reviewed 5 years of trip logs for the planes as part of its report, and it found that Michigan State's head men's basketball coach Tom Izzo and Michigan State head football coach Mark Dantonio were among the most frequent fliers.

Izzo had traveled at least 55 times in the 5-year period; Dantonio had at least 47 trips in 5 years, the newspaper found.

University spokesman Jason Cody said the school is complying with verbal requests from the FAA for documents and information, and he confirmed that the FAA is seeking records pertaining to flights that involved athletic coaches and staff.

The review is of MDOT's "use of aircraft," but details aren't released because the review is ongoing, said FAA spokeswoman Elizabeth Cory.

Flights for recruiting trips are paid for by the school's athletics department budget. The athletics department pays MDOT a per-hour fee to use the planes, officials said, and the state planes are one of several charter options that the athletics department uses.

In all, Michigan State University employees and guests used the state planes at least 150 times during the 5-year period analyzed by the newspaper, and at least two-thirds of the passengers on those trips were affiliated with the athletics department.