The Experimental Aircraft Association is asking a federal appeals court to review payments to the Federal Aviation Administration for air traffic control services during its annual convention.
EAA filed a petition with the U.S. Court of Appeals for the Seventh Circuit in Chicago on Wednesday.
In May, the FAA told EAA officials the cost for 87 air traffic controllers and supervisors to come to Oshkosh for AirVenture would be $447,000.
Last month, AirVenture made a partial payment with the remaining sum to be paid after the FAA completes its duties at the convention.
EAA is asking the appeals court to reverse the FAA's decision to demand the payment and return the money already paid.
FAA spokesman Tony Molinaro said in an email Friday he couldn't comment on pending legal actions.