“O’Hare Tower, We Have Your Numbers”
Since the beginning of aviation, the primary means of pilot-controller communication has been voice over the radio. By the late 1950s, air traffic control radio frequencies were becoming congested.
A serious bottleneck was the tower control frequency. As aircraft arrived in the terminal area, pilots would contact the tower and request the current airport information. The controller would respond with cloud conditions, altimeter setting, wind speed and direction, active runway, and any other information the pilots needed to know. This worked fine when an airport had a handful of arrivals each hour. Busy airports, like Chicago, had so many arrivals that tower controllers spent most of their time repeating the same information to every pilot. There had to be a better way…
In an effort to relieve the congestion, pilots would often monitor the tower frequency early, hoping to overhear the controller issue the information to another pilot. When it came time to call the tower, pilots would report “we have your numbers,” saving the controller from repeating the same information. This technique helped, but was far from a satisfactory solution.
1964: A Solution Emerges
In early 1964, the FAA began testing a service to give pilots timely airport information without burdening air traffic controllers. Chicago, Van Nuys, New York, and San Francisco/Oakland where the first airports to test the new system called ATIS – Automatic Terminal Information Service.
The idea was simple. Each hour, a controller records the current airport conditions. The recording is broadcast on a loop using local navigation aids (usually a VOR).
When an aircraft approaches an airport, the pilots tune in the VOR frequency and listen to the repeating message. Pilots preparing to depart listen to the recording at their convenience before taxiing. Tower controllers could now devote more time to keeping airplanes separated instead of repeating information.
ATIS worked beautifully and was fast-tracked for busy airports. By 1968, 60 airports had ATIS. Larger airports began broadcasting on dedicated VHF voice frequencies to make it more convenient for pilots. In 1974, ICAO defined its use internationally.
ATIS Format and Example
The content of U.S. ATIS has changed very little since 1964:
- Airport name, designator, zulu time
- Wind direction & speed
- Visibility and weather
- Cloud conditions
- Temperature & dew point
- Altimeter setting
- Runway(s) in use
- Comments or special information
ATIS is usually updated once an hour; 30 minutes at some airports. If the weather or airport conditions change significantly before the next version is due, a new message is recorded immediately with the word “special” added after the zulu time. This alerts pilots that a significant change has occurred.
Here’s an ATIS recorded in 2014 at Rockford International airport (KRFD) near Chicago. The transcription follows:
Rockford Tower information X-Ray, 0754 zulu.
Wind zero-eight-zero at eight
Visibility one-zero, light rain
Ceiling 2500 broken, 3300 broken, and 4500 overcast
Temperature four, dew point one
ILS runway one and ILS runway seven approaches are in use
Clearance Delivery is 119.25
Ground control is combined with tower on 118.1
Advise on initial contact you have information X-Ray
The first and last item in the recording is important. When ATIS is updated, it’s assigned a phonetic alphabet letter. The first broadcast of the day is “Information Alpha” followed by Bravo, Charlie, etc. After information Zulu, it starts over with Alpha. When a pilot contacts an approach control facility, they tell the controller they have “information X-Ray” (or whatever the current designator is). This lets the controller know the crew has current (or obsolete) information.
ATIS Outside the U.S.
Airports outside the United States generally follow the standard ICAO format, which is a little different. Runway information is provided first, followed by the weather and comments. Here’s an example from London Stansted Airport (EGSS).
Stansted information Hotel, time 2150
Runway in use: two-two. Expect an ILS approach
Ground is closed, delivery is closed
Surface wind two-one-zero, one-one knots
Visibility one-zero kilometers or more
Broken 700 feet, overcast 1100 feet
Temperature: plus niner, dew point plus eight
QNH: niner-eight-two hectopascal
Transition Level: Flight Level seven zero
Runway two-two: wet-wet-wet
Acknowledge receipt of information Hotel and advise aircraft type on first contact
A few differences between ICAO and US ATIS: Visibility is given in Kilometers instead of statute miles. Altimeter setting is usually in hectopascal instead of inches of mercury. Transition level is sometimes provided to remind pilots when to adjust altimeters to the local setting.
The runway condition provided by Stansted (Runway two-two, wet-wet-wet) means that each third of runway 22 (touchdown, midfield, rollout) is wet.
Advances in ATIS Technology
ATIS changed very little from the 1960s to the 1990s. New recording equipment came along, but controllers still updated the looped recordings by reading into a telephone handset.
In 1996, ATIS entered the digital age when Houston Intercontinental introduced data link ATIS (D-ATIS) over ACARS. The new system allows pilots to receive ATIS hundreds of miles from the destination. [ACARS is a digital data link technology that allows pilots to exchange text information with their company.]
To create a D-ATIS message, air traffic controllers use a menu interface to enter airport information into the system. Current weather is often imported automatically. The process to update D-ATIS takes only a few seconds.
Most major airports around the world have upgraded to data link ATIS.
Airports with D-ATIS still provide an audio broadcast for pilots that don’t have ACARS equipment. The D-ATIS system uses text-to-speech technology to convert the message to a synthetic voice. It’s fun to listen to D-ATIS broadcasts around the world. Different airports use different speech systems. Newer systems have natural sounding voices and even incorporate local accents. The audio example above from Stansted airport is a synthetic voice.
Benefits of Data Link ATIS
D-ATIS provides a big safety enhancement for aircraft crews. To receive an audio ATIS, one crew member must monitor a separate frequency and write down the information during a high workload phase of flight. Textual D-ATIS information can be received during cruise and reviewed at the crew’s leisure.
Other benefits of D-ATIS:
- Controller can update the current information in seconds
- Can be printed if the aircraft has a printer
- Reading D-ATIS increases comprehension (audio is often difficult to understand)
- Separate arrival and departure messages can be created (pictured below)
ATIS at Small Airports
Tower controlled fields that have low traffic volume or cater to small aircraft often use the classic, human-recorded broadcast. Many general aviation planes lack data link equipment, so there isn’t much benefit for a small airport to upgrade to D-ATIS. And it’s always nice to hear a human voice once in a while.
Bowman Field (KLOU) serves the general aviation community around Louisville, KY. Unlike it’s busy neighboring airport (Louisville International) located a few miles west, Bowman Field hosts private planes, helicopters, flight school aircraft, and small business aircraft.
Here’s an old-school ATIS from Bowman…
How do pilots find ATIS?
It’s on our charts! Airport diagrams (maps) and approach charts show the frequency for listening to the ATIS broadcast. The charts also indicate if the ATIS has a data link version. If the chart shows “D-ATIS,” pilots know it’s available via ACARS.
English is considered the international language of aviation. A few places in the world support dual language air traffic control. Controllers in these locations speak both ICAO Aviation English and the local language. Even ATIS is sometimes provided in two languages!
Quebec City and Montréal airports broadcast in both French and English on separate frequencies.
Airports in China broadcast a dual language ATIS on a single frequency, alternating Mandarin and English versions (audio examples below).
Data link ATIS is always transmitted in English.
Audio may not be available in all browsers. If you can’t see the audio controls below, try a different browser.
Prerecorded ATIS broadcasts from around the planet!
Click highlighted airport identifiers to see print out
|Anchorage, USA PANC
||Osaka (Kansai), Japan RJBB
|Clark, Philippines RPLC||Penang, Malaysia WMKP
|Cologne-Bonn, Germany EDDK
||Rockford, USA KRFD
|Ho Chi Minh, Vietnam VVTS||Shanghai, China (dual language) ZSPD
|Incheon, South Korea RKSI
||Shenzhen, China (dual language) ZGSZ|
|Kuala Lumpur, Malaysia WMKP
||Changi, Singapore WSSS
|Louisville, USA KSDF
||Winnipeg, Canada CYWG
|Newark, USA KEWR
||Zhengzhou, China (dual language) ZHCC
ATIS is Serious Business (most of the time)
Air traffic controllers occasionally put a little fun into the ATIS. Holiday greetings are common but other special occasions are often mentioned. Here’s a holiday greeting from Kelowna International Airport in British Columbia (audio clip from SoundCloud)
After France won the 2018 FIFA World Cup, Côte d’Azur Airport (LFMN) in Nice included a special victory message in the NOTAM (Notices to Airmen) section of their ATIS.
ATIS on the Internet
It would be helpful (and fun) if audio or data link ATIS were available on the internet. Unfortunately, live ATIS is tough to find online. With a few exceptions, official broadcasts can only be received on aircraft VHF frequencies or from an aircraft data link vendor.
Official ATIS Feeds
I found two places where official ATIS is available to the public from the airport authority:
Czech Republic Air Navigation Services provides data link ATIS on its website for Prague, Brno, Ostrava, and Karlovy Vary airports. Visit the Czech Republic’s Integrated Briefing System, click the “ATIS” tab and select an airport (no login required).
Hong Kong Civil Aviation Department provides arrival and departure ATIS for Hong Kong International.
If you know of any other official feeds available to the public, let me know in the comments and I’ll add them!
Unofficial ATIS Rebroadcasts
The best place to find rebroadcast ATIS audio is LiveATC.net. The website relies on volunteers to stream local air traffic control broadcasts to LiveATC servers. Quality of the streams varies considerably.
On the LiveATC homepage, enter your favorite airport code (like JFK or KJFK) into the Airport/ARTCC search box to see if an ATIS frequency is available.
If you want to see all the airports on LiveATC with an ATIS feed, enter “ATIS” in the Site-wide search box. The search will generate pages of results.
ATIS on Twitter
Airservices Australia provides ATIS online for several airports, but only for registered pilots. A Twitter user has created a bot that pulls Airservices data and tweets the current ATIS for the following airports:
|@YBCSATIS (Cairns)||@YBCGATIS (Gold Coast)|
|@YSSYATIS (Sydney)||@YPADATIS (Adelaide)|
|@YPPHATIS (Perth)||@YMMLATIS (Melbourne)|
|@YBBNATIS (Brisbane)||@YMAVATIS (Avalon)|
Know of other online ATIS resources? Let me know in the comments!
In loving memory of our son Casey
Point Foundation scholar, GLSEN board member, artist, activist, TEDx speaker, contributor to HuffPost Teen & MTV News, and Disney trivia master °o°.
Your light shined incredibly bright. We were so lucky to have you. Rest in Power. ❤