The U.S. Court of Appeals for the District of Columbia rejected an airline industry challenge to a regulation letting airport operators charge more at busy times of the day to reduce delays.The carriers argued the July 2008 regulation by the Transportation Department was discriminatory and unreasonable. The airlines also claimed the regulation wrongfully allowed state and local airport authorities to charge fees preempted by federal law and provided inadequate guidance to the airports on how the Department of Transportation would evaluate the reasonableness of the fees.The court denied the petition by the Air Transport Association, which represents companies including Delta Air Lines Inc. and AMR Corp., the owner of American Airlines.The full opinion in case Air Transport Association of America Inc. v. U.S. Department of Transportation, 08-1293, U.S. Court of Appeals for the District of Columbia is available for download here>>.