Rule 39C

ATIS and VOLMET broadcast


ATIS and VOLMET Broadcast

Explain ATIS and VOLMET broadcast..( Answer to the question in the Question Bank for RTR (A) exam)

Automatic Terminal Information Service, or ATIS, is a continuous broadcast of recorded non control aeronautical information in busier terminal (i.e. airport) areas. ATIS broadcasts contain essential information, such as weather information, which runways are active, available approaches, and any other information required by the pilots, such as important NOTAMs. Pilots usually listen to an available ATIS broadcast before contacting the local control unit, in order to reduce the controllers’ workload and relieve frequency congestion.

The recording is updated in fixed intervals or when there is a significant change in the information, e.g. a change in the active runway. It is given a letter designation (e.g. bravo) from the ICAO spelling alphabet. The letter progresses through the alphabet with every update and starts at alpha after a break in service of 12 hours or more. When contacting the local control unit, a pilot will indicate he/she has “information <BRAHVO>”, where <B> is the ATIS identification letter of the ATIS transmission the pilot received. This allows the ATC controller to verify whether the pilot has all the current information.

The ATIS at an airport is usually given by an automated voice, this allows a busy air traffic controller to quickly type a new ATIS message (or for a computer system reading weather instruments to generate parts of the message dynamically) instead of making a time-consuming voice recording, although at some smaller, less busy airports with a control tower, it may be made by a controller and not a computer. Most airports in a certain country will often have the same ATIS format or layout with the same automated voice. For example, all ATIS information at major airports in the United Kingdom such as Heathrow, Gatwick, Manchester, Birmingham, Edinburgh and even smaller ones, such as East Midlands and Newcastle, have a similar format or layout and are all given by the same automated voice.

VOLMET

VOLMET (French origin VOL (flight) and METEO (weather)), or meteorological information for aircraft in flight, is a worldwide network of radio stations that broadcast TAF, SIGMET and METAR reports on shortwave frequencies, and in some countries on VHF too. Reports are sent in upper sideband mode, using automated voice transmissions.

Pilots on international routes, such as North Atlantic Tracks, use these transmissions to avoid storms and turbulence, and to determine which procedures to use for descent, approach, and landing.

The VOLMET network divides the world into specific regions, and individual VOLMET stations in each region broadcast weather reports for specific groups of air terminals in their region at specific times, coordinating their transmission schedules so as not to interfere with one another. Schedules are determined in intervals of five minutes, with one VOLMET station in each region broadcasting reports for a fixed list of cities in each interval. These schedules repeat every hour.

References

  1.  Wikipedia
  2. Meteorology book of FIS