Air Station

The Washington, D.C. airport was an airport before the bombs fell. Some time after the bombs fell, a group of people trying to gain entry to Vault 101 used the scrap from the planes and buildings at the airport as building materials to create the town of Megaton. Over time, the rest of the airport was reclaimed by nature; no sign of its existence remains.

Appearances
Washington, D.C. airport is mentioned in Fallout 3.

Behind the scenes
The airport could be Ronald Reagan or Dulles airport, as in Fallout, the airport was not far from Megaton, said by Manya, and Dulles, as well as Ronald Reagan, are located nearby. Neither actually appear in the Capital Wasteland.