Clear communication between pilots and air traffic controllers is absolutely necessary for safety. What happens when a flight crew flies to a country that speaks a different language? Just imagine: an Air China flight crew that speaks Mandarin arrives in Paris and must converse with French controllers. In order to communicate effectively, flight crews and controllers must share a common language.
In 1951, when international air travel really started to take off, the International Civil Aviation Organization (ICAO) recommended that English be the standard language for aviation communications. Why English? At the time, the US and UK manufactured and operated the majority of the world’s aircraft. Native Anglophones, consider yourself lucky!
ICAO Aviation English: The Script
ICAO publishes a special vocabulary of Aviation English words and phrases that all international pilots and air traffic controllers must learn. ICAO even stipulates how the words, letters and numbers should be pronounced! We sometimes call the phrases “The Script.” The script is designed to cover just about any situation that might arise, including emergencies.
Here’s a sample of how picky the guidelines are. Click the charts below to learn the proper pronunciation of letters and numbers. Have you ever heard pilots in movies and TV say things like: “Trans-Global four-one-seven, Turn left two-niner-zero and fly direct to Charlie-Zulu-India?” THIS is why!
As you can imagine, even with a common language, communication can still be challenging due to different accents around the world. When communicating with one another, flight crews and controllers usually say specific things at certain times. Just like actors following a script, the participants can anticipate what will be said and when. As long as everyone stays on the script, things run smoothly.
Everyone’s Favorite Flight Crew
Captain Clarence Oveur, First Officer Roger Murdock, and Engineer Victor Basta having a little fun with ICAO Aviation English (from “Airplane!” ©Paramount Pictures, 1980):
Do pilots and controllers speak only English on the radio?
Nope! ICAO Aviation English is a recommendation, not a law. Although English is common, we often hear other languages on the radio. Air traffic controllers in the Canadian province of Quebec are famous for speaking both French and English. A friendly, properly accented “Bonjour, Montréal Centre!” when checking in will let them know you prefer French. In the interest of aviation safety, I always say “Hello” or “Good Morning.” 🙂
Controllers in China speak Mandarin to Chinese pilots, and English to out-of-towners. It’s amazing to fly into Beijing or Shanghai at rush hour and hear the controllers rattling off clearances in both languages; they never miss a beat. Here’s an example of a bilingual ATIS from Shanghai’s Pudong International Airport. ATIS (Automated Terminal Information Service) is a recorded message (usually computer generated) that is transmitted at large airports. The ATIS reports current weather, runways in use and other general information that pilots need to know before takeoff or landing. The first part is in English, then repeated in Mandarin.
Update (Dec, 2016): Sometime in 2017, the Civil Aviation Administration of China (CAAC) will mandate that its air traffic controllers use only English when communicating with pilots. This will improve situational awareness for all pilots operating in China.
Update (2020): The mandate mentioned in the previous update never happened. I don’t anticipate any change to the dual language ATC in China.
Is it easy to understand the “English” in different countries?
It’s challenging, but everyone tries to follow the ICAO script to minimize problems. Occasionally, a heavy accent or fast talker will throw a wrench into communications. A simple request of “Confirm?,” “Say again?” or “Speak slower” will usually help clear up the confusion. Even the ATIS broadcast above follows a script; the information is presented in the same order at every international airport. Flight crews know what to listen for and can pick out the important information.
Practice and Familiarity
The first time I flew in Asia, I can’t remember how many times I heard stuff on the radio then asked my First Officer: “What did he say?” After a couple of weeks of Asia flying, I become familiar with the routes and the typical requests and clearances. Understanding the Chinese, Japanese, and Korean controllers and being able to anticipate what they were going to say became much easier. The same is true for different areas of the world.
Here is a 4 minute clip of Taipei Control directing arriving and departing flights in Taipei, Taiwan. In the clip you’ll hear the controllers talking to several airlines: Dynasty (China Airlines), Delta, Asiana, Cathay Pacific, Korean Airlines, EVA, and Air Hong Kong.
At 2:20 in the clip you’ll hear the controller confirming how many miles off-course a Korean Air flight wants to fly to avoid bad weather. The Korean pilot’s accent made it difficult for the Taiwanese controller to understand the request. She did a great job making sure both of them understood exactly what the pilot needed.
What countries are extra challenging? Which ones are easy?
The answer to this question varies from person to person. Ask a German Lufthansa pilot and he or she will have a very different answer than a U.S. based pilot. For me, Japan is easy; most of Europe and the Middle East are a piece of cake. For some reason, I find France challenging; it must be the French accents. I’m always listening with both ears when flying into Paris. Operating in India is tricky as well. The airspace around Mumbai (Bombay) is very busy and the controllers issue rapid-fire clearances. You often hear western pilots asking Mumbai controllers to slow down and repeat clearances.
One of the easiest countries I’ve flown over might come as a surprise, given the political climate. A few years ago we began flying over Iran’s airspace on our Dubai-Cologne route. Overflying Iran saves us quite a bit of time and fuel (and money). What a nice experience! The Iranian controllers are friendly and their English is excellent. The scenery is beautiful, too. The photo was taken over Maharloo Lake near Shiraz, Iran.
What if Airbus had been building hundreds of airplanes in the 1950’s?
Had Airbus been booming in the ’50’s, Le Français would likely be the international language of aviation. French was on the short list of languages being considered. In fact, the French language provides many common aviation words: Aileron, fuselage, and empennage are of French origin. The familiar distress call: “Mayday!” is derived from “M’aider,” French for “help me.” Many abbreviations used in international weather reports are derived from French meteorological terms. Où est l’aéroport? Allons-y!
“Say Again?” Phraseology Database – Provided by EuroControl, this is a fun way to explore Aviation English. Click around to see the different phrases pilots and controllers must learn.
The following two documents are the international “bibles” of ICAO aviation communication. They are difficult to read and will put you to sleep faster than an Ambien overdose. Really, you don’t want to read these things.
ICAO Annex 10: Aeronautical Telecommunications (PDF)
ICAO Doc 4444: Air Traffic Management (PDF)