Automatic terminal information service

{{Short description|Broadcast of aeronautical information}}

Automatic terminal information service, or ATIS, is a continuous broadcast of recorded aeronautical information in busier terminal areas. ATIS broadcasts contain essential information, such as current weather information, active runways, 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, which reduces the controllers' workload and relieves frequency congestion.{{cite book|author=Federal Aviation Administration|title=Federal Aviation Regulations/Aeronautical Information Manual 2009 (FAR/AIM 2009)|url=https://books.google.com/books?id=kghrCgAAQBAJ&pg=SL1-PA16|date=November 2008|publisher=Skyhorse Publishing Inc.|isbn=978-1-60239-298-4|pages=1–}} ATIS was developed and adopted by the FAA in the mid-1960s and internationally (under the direction of ICAO) beginning in 1974. Before the adoption of ATIS, this information was routinely disseminated to each aircraft separately, increasing controller workload during periods of high traffic density.{{Cite web |title=ATIS Archives - AeroSavvy |url=https://aerosavvy.com/tag/atis/feed/ |access-date=2023-09-04 |website=aerosavvy.com}}

In the U.S., ATIS will include (in this order): the airport or facility name; a phonetic letter code; time of the latest weather observation in UTC; weather information, consisting of wind direction and velocity, visibility, obstructions to vision, sky condition, temperature, dew point, altimeter setting, density altitude advisory if appropriate; and other pertinent remarks, including runway in use. If it exists, the weather observation includes remarks of lightning, cumulonimbus, and towering cumulus clouds. Additionally, ATIS may contain man-portable air-defense systems (MANPADS) alert and advisory, reported unauthorized laser illumination events, instrument or visual approaches in use, departure runways, taxiway closures, new or temporary changes to runway length, runway condition and codes, other optional information, and advisories.

The recording is updated in fixed intervals or when there is a significant change in the information, such as a change in the active runway. It is given a letter designation (alpha, bravo, charlie, etc.) from the ICAO spelling alphabet.{{Cite web|url=https://www.icao.int/Pages/AlphabetRadiotelephony.aspx|title=Alphabet - Radiotelephony|website=www.icao.int}} The letter progresses through the alphabet with every update and starts at alpha after a break in service of twelve hours or more. When contacting the local control unit, pilots indicate their information , where is the ATIS identification letter of the ATIS transmission the pilot received. This helps the ATC controller verify that the pilot has current information.{{cite book|author=David Harrison|title=Pilot's Guide to ATC|url=https://books.google.com/books?id=9qfLE2jI9iAC&pg=PT276|year=2008|publisher=Trafford Publishing|isbn=978-1-4251-3270-5|pages=276–}}

Many airports also employ the use of data-link ATIS (D-ATIS, introduced in 1996). D-ATIS is a text-based, digitally transmitted version of the ATIS audio broadcast. It is accessed via a data link service such as the ACARS{{cite web|url=http://www.eurocontrol.int/acars/public/standard_page/overview.html |title=EUROCONTROL - Overview |access-date=2012-06-04 |url-status=dead |archive-url=https://web.archive.org/web/20130211030933/http://www.eurocontrol.int/acars/public/standard_page/overview.html |archive-date=2013-02-11 }} and displayed on an electronic display in the aircraft. D-ATIS is incorporated on the aircraft as part of its electronic system, such as an EFB or an FMS. D-ATIS may be incorporated into the core ATIS system or be realized as a separate system with a data interface between voice ATIS and D-ATIS.

The ATIS is not to be confused with the METAR, which will not contain certain information such as the runway in use.