About Ground Stations
The FCC regulates the Aviation Services in cooperation with the Federal Aviation Administration. Wherever aviation services are provided in US territory, both FAA and FCC requirements must be met by anyone who uses aviation radio. The FCC authorizes different types of aviation ground stations for air-to-ground operations. Flight safety is the primary purpose of all Aviation Services.
Aeronautical and Fixed Service
Aeronautical advisory stations, also called Unicom stations, are land stations used for advising pilots of private aircraft about local airport conditions. They are not used to control aircraft in flight.
Aeronautical multicom stations provide communications between private aircraft and a ground facility for temporary, seasonal, or emergency activities like crop dusting, livestock herding, forest firefighting, aerial advertising, parachute jumping, etc. In some cases, multicom stations may be authorized to serve as unicom stations.
Aeronautical enroute stations are used by aircraft owners or operators for operational control and flight management of their aircraft. They have access to these stations by cooperative arrangement, but any pilot with a flight emergency may use these stations without prior agreement.
Flight test stations are airborne and ground stations used only to pass information or instructions concerning tests of aircraft or airborne components.
Aviation support stations are airborne and ground stations used for pilot training, soaring (with gliders), or free ballooning.
Airport control tower stationsprovide all necessary communications between an airport control tower and all arriving and departing aircraft. They are used to maintain an efficient flow of traffic for aircraft taxiing, landing, and takeoff and for all vehicle movement on the airfield. For vehicle movement on the airfield, airport control tower stations communicate with aeronautical utility mobile stations
Automatic weather observation stations provide updated weather broadcasts for a specific landing area.
Aviation Auxiliary Group
Aeronautical search and rescue stations are used for air-to-ground communications during actual or practice search and rescue operations, or for search and rescue training.
Aeronautical utility mobile stations are installed in vehicles that provide maintenance, fire and crash protection, freight handling, or other group support normally under control tower direction at an airport. They are used for both operational and emergency communications.
Aeronautical Radionavigation Service
The Aeronautical Radionavigation Service is made up of stations used for navigation, obstruction warning, instrument landing, and measurement of altitude and range. Air radionavigation stations stations are usually operated by the Federal Aviation Administration (FAA), so technically they are not radio services regulated by the FCC. The FCC does license some air radionavigation stations, however; if air radionavigation service is needed where the FAA does not provide it, the FCC authorizes private operators to provide the service, in strict compliance with the FAA requirements.
Radionavigation stations also include radar, radiobeacons, and these other aids to air navigation:
Glide path stations are directional radiobeacons associated with instrument landing systems used to guide the descent of aircraft in landing.
Marker beacons are transmitters that radiate vertically to provide positioning information to aircraft in flight.
Omni-directional range stations (VOR) transmit signals in all directions from which aircraft can determine their bearing.
Land Test Stations transmit signals for testing and calibrating air navigation aids.
Nondirectional Radiobeacon stations (NDB) transmit nondirectional signals whereby the pilot of an aircraft can determine bearings and “home” on the station.
Localizer stations provide the pilot with course guidance to the runway centerline.
Radionavigation land stations (DME) provide distance measuring from the aircraft to the ground station.