39th MDG welcomes new commander Published Aug. 7, 2015 By Senior Airman Krystal Ardrey 39th Air Base Wing Public Affairs INCIRLIK AIR BASE, Turkey -- Col. Thomas Bacon took command of the 39th Medical Group during a change of command ceremony here, Aug. 7. Prior to taking command, Bacon was the commander of the 99th Medical Operations Squadron, Nellis Air Force Base, Nev. A change of command ceremony is a tradition that represents a formal transfer of authority and responsibility from the outgoing commander to the incoming commander.