automated terminal information service

The automatic provision of current, routine information to arriving and departing aircraft throughout 24 h or a specified portion thereof (ICAO). ATIS is the continuous broadcast of recorded non-control information in selected high-activity terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential but routine information. The information is broadcast over a discrete VHF radio frequency or the voice portion of a local navigational aid. These transmissions can be received to a maximum distance of 60 NM and a maximum altitude of 25,000 ft. The ATIS information includes the time of the latest weather sequence, ceiling, visibility, obstructions to visibility, temperature, dew point (if available), wind direction and velocity, altimeter setting, and other pertinent remarks, instruments, and runways in use. The ceiling/sky conditions, visibility, and obstructions to visibility may be omitted provided the ceiling is above 5000 ft and visibility is more than 5 miles. The departure runway is given only if it is different from the landing runway except at those locations that have a separate ATIS for departure. The broadcast also may include appropriate frequency and instructions for VFR arrivals to make initial contact with approach control. There are two types of ATIS. Data-linked automatic terminal service (D-ATIS) provides the service via data link, while voice-automatic terminal service (voice-ATIS) provides information by means of continuous and repetitive broadcasts.