The drawing was done at Gravelly point, which overlooks Ronald Reagan Washington National Airport (KDCA) on the north side. I first sketched out the line of runway distance signs (labeled 6, 5, 4, etc.), which let pilots know how much space remains for their takeoff roll. I then sketched a “2” sign from runway 33-15, which intersects KDCA’s main runway. With a little artistic revising, the two runways combine to form a plane.