A Terminal Radar Approach Control or FAA TRACON in the United States) is an Air Traffic Control facility usually located within the vicinity of a large airport. Typically, the TRACON controls aircraft within a 30-50 nautical mile (56 to 93 km) radius of the airport between the surface and 18,000 feet. A TRACON is sometimes called Approach Control or Departure Control in radio transmissions. In The US Air Force it is known as RAPCON (Radar Approach Control), and in the US Navy as a "RATCF" (Radar Air Traffic Control Facility) In Canada, Approach Control may be called Arrival or Terminal.