It's fairly obvious when you look at the map: https://www.google.com/maps/place/Ronald+Reagan+Washington+National+Airport/@38.9443854,-77.1246524,11.39z/data=!

It's fairly obvious when you look at the map: https://www.google.com/maps/place/Ronald+Reagan+Washington+National+Airport/@38.9443854,-77.1246524,11.39z/data=!4m5!3m4!1s0x89b7b731402fe095:0x4168af016d076bad!8m2!3d38.851242!4d-77.0402315 https://www.google.com/maps/place/Ronald+Reagan+Washington+N... Left is upstream and away from DC. Right is towards restricted airspace.