They probably weren't. At that point the training was over. They departed Langley, entered Helicopter Route 4 and were returning to Davison Army Airfield (Belvoir).
In the DC area where helicopters can fly, even military, is extremely restricted. If, for whatever reason you were going to fly over the Mall you landed at Anacostia and picked up a couple of secret service members. And that mission would be cleared by them well before that.