Listening to the BWI liveatc.net feed today, I heard a TN9WR callsign check in, landing Gaithersburg, MD. I looked on FA, and the callsign was valid. What would be the reason for tacking on the T infront of the tail number?
Edit: It just occured to me, after looking at the flight history, that this could be an air taxi operation. Am I correct in thinking this?