background image Pilot/Controller Glossary AUTOMATIC DEPENDENT SURVEILLANCE - BROADCAST IN (ADS - B In) - Aircraft avionics capable of receiving ADS - B Out transmissions directly from other aircraft, as well as traffic or weather information transmitted from ground stations. (See AUTOMATIC DEPENDENT SURVEILLANCE - BROADCAST OUT.) (See AUTOMATIC DEPENDENT SURVEILLANCE - REBROADCAST.) (See FLIGHT INFORMATION SERVICE - BROADCAST.) (See TRAFFIC INFORMATION SERVICE - BROADCAST.) AUTOMATIC DEPENDENT SURVEILLANCE - BROADCAST OUT (ADS - B Out) - The transmitter onboard an aircraft or ground vehicle that periodically broadcasts its GNSS - derived position along with other required information, such as identity, altitude, and velocity. (See AUTOMATIC DEPENDENT SURVEILLANCE - BROADCAST.) (See AUTOMATIC DEPENDENT SURVEILLANCE - BROADCAST IN.) AUTOMATIC DEPENDENT SURVEILLANCE - CONTRACT (ADS - C) - A data link position reporting system, controlled by a ground station, that establishes contracts with an aircraft's avionics that occur automatically whenever specific events occur, or specific time intervals are reached. AUTOMATIC DEPENDENT SURVEILLANCE- REBROADCAST (ADS-R) - A datalink translation function of the ADS - B ground system required to accommodate the two separate operating frequencies (978 MHz and 1090 MHz). The ADS - B system receives the ADS - B messages transmitted on one frequency and ADS - translates and reformats the information for rebroadcast and use on the other frequency. This allows ADS - B In equipped aircraft to see nearby ADS - B Out traffic regardless of the operating link of the other aircraft. Aircraft operating on the same ADS - B frequency exchange information directly and do not require the ADS - translation function. AUTOMATIC DIRECTION FINDER - An aircraft radio navigation system which senses and indicates the direction to a L/MF nondirectional radio beacon (NDB) ground transmitter. Direction is indicated to the pilot as a magnetic bearing or as a relative bearing to the longitudinal axis of the aircraft depending on the type of indicator installed in the aircraft. In certain applications, such as military, ADF operations may be based on airborne and ground transmitters in the VHF/UHF frequency spectrum. (See BEARING.) (See NONDIRECTIONAL BEACON.) AUTOMATIC FLIGHT INFORMATION SERVICE (AFIS) - ALASKA FSSs ONLY - The continuous broadcast of recorded non - control information at airports in Alaska where a FSS provides local airport advisory service. The AFIS broadcast automates the repetitive transmission of essential but routine information such as weather, wind, altimeter, favored runway, braking action, airport NOTAMs, and other applicable information. The information is continuously broadcast over a discrete VHF radio frequency (usually the ASOS/AWOS frequency). AUTOMATIC TERMINAL INFORMATION SERVICE - The continuous broadcast of recorded noncontrol information in selected terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential but routine information; e.g., "Los Angeles information Alfa. One three zero zero Coordinated Universal Time. Weather, measured ceiling two thousand overcast, visibility three, haze, smoke, temperature seven one, dew point five seven, wind two five zero at five, altimeter two niner niner six. I-L-S Runway Two Five Left approach in use, Runway Two Five Right closed, advise you have Alfa." (See ICAO term AUTOMATIC TERMINAL INFORMATION SERVICE.) (Refer to AIM.) AUTOMATIC TERMINAL INFORMATION SERVICE [ICAO] - The provision of current, routine information to arriving and departing aircraft by means of continuous and repetitive broadcasts throughout the day or a specified portion of the day. AUTOROTATION - A rotorcraft flight condition in which the lifting rotor is driven entirely by action of the air when the rotorcraft is in motion. -