Like the other poster said, DCA is what the base is called for bidding purposes, but the majority of the flying and all administrative services are out of IAD. A Dulles-based NB pilot will also fly out of DCA and BWI. WB flying is out of IAD.

Not really sure if I understand what you are asking about reserves. Reserves cover whatever is needed, so they could be out of any airport mentioned above — you wouldn’t know that in advance to an assignment.

Edit…. Like dmeg said. If you’re looking for an answer to a different question, you might want to rephrase it.