Automatic Terminal Information Service
From Free net encyclopedia
Automatic Terminal Information Service, or ATIS, is a continuous broadcast of recorded noncontrol information in busier terminal (i.e. airport) areas. ATIS broadcasts contain essential information, such as cloud base height, wind speed and direction, visibility, temperature, dew point, the active runway, altimeter settings, and any other information required by the pilots. Pilots usually listen to an available ATIS broadcast before contacting the local control tower, in order to reduce the controllers' workload and relieve frequency congestion. The recording is updated when there is a significant change in the information, like a change in the active runway. It is given a letter designation (e.g. bravo), from the Phonetic Alphabet. The letter progresses down the alphabet and starts at Alpha each day. When contacting the control tower or ground station, a pilot will indicate he/she has "information" and the ATIS identification letter to let the controller know that the pilot is up to date with all current information.
On tuning to an ATIS frequency, a pilot might hear:
- This is Langley Airport Information Bravo. Weather at one three five five zulu. Wind three zero zero at eight, visibility five. Flight conditions: Five hundred scattered, one thousand two hundred few, three thousand overcast, temperature one five, dew-point zero eight. Altimeter two niner eight seven. IFR approach 19. Landing and departures 19. GPS approaches available. Inform ATC on initial contact you have bravo.
This translates to: Langley Airport, the information Bravo is issued at 13:55 UTC. The winds are from 300 at 8 Knots. Five statute miles visibility. At 500 feet there is scattered cloud, at 1,200 there are few clouds, at 3,000 feet its overcast. The temperature is 15C (some airports don't include this due to variability). The dew point is 8C. The altimeter is 29.87 inches of Mercury, however this could also be expressed in millibars or hectopascals. IFR approaches are on runway 19, the active runway is 19. You can conduct an approach via a GPS system. When you first contact air traffic control inform them that you have information bravo.