A federal appeals court Tuesday ruled in favor of the Federal Aviation Administration in its three-year battle with D.C. residents over noise from Reagan National Airport, handing the agency a significant victory as it moves forward with efforts to modernize the nation’s antiquated air traffic system.

A three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit said that while the residents’ argument had “some appeal,” their case would not be considered because they had missed the deadline for filing their complaint.

Residents of Georgetown, the Palisades and other Northwest Washington neighborhoods, who filed suit in 2015, maintained that they were not given adequate notice of changes to flight patterns that resulted in a significant increase in noise from planes taking off and landing at National.

In a unanimous decision, however, the judicial panel said the residents’ argument ran into “procedural and substantive obstacles.”