AT: "at" Third Academy Training Wing was a Starfleet Academy unit of flight trainers in operational use in the late 2360s. This unit consisted of a number of squadrons, including Falcon Squadron, and was commanded by Captain David Livingston. One of the wing's pilots, Harry Kim, flew a trainer for Falcon Squadron. (VOY: "Non Sequitur")
The name for this training wing comes from a Flight Proficiency Award. This document was presented for auction as a part of the set "Harry Kim Office and Apartment Set Dressing Lot" in the It's A Wrap! sale and auction. [1]