Went out to the Udvar Hazy Museum just outside Dulles International Airport yesterday....
Nice shots! That is a great place for a little plane spotting. Have you been to Gravelly Point as well?
Surprised you were able to get to an area that afforded such good imaging. Around here they still run you off if you hang around the airport side roads and even the roads where one use to be able to just sit, enjoy a snack and watch planes come and go all day. Being anywhere near the landing and takeoff runways (outside the fences and barriers, of course) is still a no-no. Airport police and the private contracted police are vigilant.
Again, very nice shots.