A federal appeals court on Tuesday ordered dismissal of a lawsuit that US Airways pilots filed against a federal agency in a fight over pension benefits, saying the claims must be pursued through administrative channels.

In a 3-0 ruling, the U.S. Court of Appeals for the District of Columbia Circuit sent the case back to a lower federal court with instructions to dismiss the pilots’ suit against the Pension Benefit Guaranty Corp., the federal agency that backs private pension plans. Without ruling on the merits of the case, the appeals court said the November 2003 suit must be thrown out “because the pilots have not yet exhausted their administrative remedies.”