Run-in for a military funeral at Arlington Cemetery.
Usually done on a different axis but depending upon where the burial plot is, can fly over Rockville.
reasonable explanation and very possible.
The Marine Corps Lt. Colonel who was killed in Afghanistan last week is to be buried in Arlington National Cemetery.
i used to work on rt395 and see them once or twice a week. never seen them here. a formation of 3 with 4th a mile or more back right