Everything seemed to be on normal frequencies. My post on the "Sticky" thread recaps the primary operational callsigns and freqs used by the intercepting aircraft. All the rest of the traffic was on the normal airways freqs at Reagan National and Dulles airports. I would guess there were others that I didn't catch that were in support roles as events unfolded. I'm too far from the Frederick Airport to hear their tower and ground freqs when they finally forced the guy to land there but they are in the database.
Even if you have no use for listening to aircraft traffic, it might be a good idea to have the DC-ANG frequencies loaded up for emergency situations such as this. I thoroughly enjoy listening to their missions as they practice for this type event and almost any other contingency event they can think of. Those guys are good, very good, at what they do.