Under investigation by the U.S. Department of Transportation’s inspector general and the FBI, the embattled Metropolitan Washington Airports Authority is also facing a legal challenge to its plan to extend Metrorail to Washington Dulles International Airport and beyond.

On Oct. 2, the U.S. Court of Appeals for the Federal Circuit heard oral arguments in a class-action lawsuit claiming that the MWAA has no legal authority to raise tolls on the Dulles Toll Road in order to pay for the Silver Line.