ATC phraseology for beginners

Listen to an airport's radio for five minutes and you will hear a language that sounds like English but follows strict rules. Every call is short. Numbers are spoken one digit at a time. Some words are never used for anything except one meaning. That is deliberate. A radio channel is shared, often noisy, and sometimes two people talk at once, so the words have to be clear the first time.

This guide explains the most common phrases, the format of a call and how numbers and letters are spoken. It uses the phrases that appear in real practice and in the game's radio strip, which tries to follow them.

The format of a call

A radio call has three parts, and they come in the same order almost every time.

1. Who you are calling. "Atlanta Ground" or "Tower".
2. Who you are. Your callsign, the name of the aircraft or the airline and flight number.
3. The message. What you want, or what you are telling the other side.

A typical call from a pilot might be "Atlanta Ground, Delta one two three, at the gate, request taxi." The controller answers with the callsign and the instruction: "Delta one two three, taxi to runway two six via Charlie." The crew then reads the instruction back, and the controller checks it.

Once the first call is made, controllers often shorten the callsign to save air time, for example just the flight number. Do not be surprised if you hear that. The aim is to keep the channel clear, not to be polite.

The phrases you will hear most

These are the words that matter most. Meanings are the usual ones in practice.

Two of these words cause the most confusion. "Roger" means the message was received, and it is often mistaken for yes. "Wilco" means the instruction will be followed. If a controller wants a yes or no, they ask a direct question, and the reply is "affirm" or "negative".

Clearances and readbacks

A clearance is permission to do something, and it is always read back. The pilot repeats the key words: the runway, the altitude, the heading, the frequency and the restriction. The controller listens for mistakes. A correct readback ends with the controller saying "readback correct". A wrong one is corrected immediately.

Readbacks look repetitive to a newcomer, but they are one of the most important safety habits in aviation. A wrong altitude or runway read back and not corrected is exactly the kind of error the system is designed to catch.

How numbers are spoken

Numbers on the radio are said one digit at a time, so that "two six" is runway 26 and "one two zero" is a heading of 120. Altitudes are the exception in the usual way. "Five thousand" is 5,000 feet, and "flight level three three zero" is 33,000 feet on the standard pressure setting. Those rules are set in the international radiotelephony manual, ICAO Doc 9432, and in the FAA's controller handbook.

The digit nine is spoken as "niner" in radio practice, so it sounds clearly different from other words over a noisy channel. The digit three is often spoken as "tree" for the same reason. You will hear both in real traffic, and the game uses "niner" too.

Letters use the phonetic alphabet: Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, and so on through the alphabet. Runway ends with a letter are spoken as "two seven Left", "two seven Right" or "two seven Center", so two parallel runways can be told apart on the radio.

Callsigns

An airline callsign has three parts: the airline's three-letter ICAO code, spoken as a word, and the flight number. Delta flight 123 is called "Delta one two three". Private planes use their registration, for example "November one two three Alpha Bravo", where the letters are spoken in the phonetic alphabet.

Callsigns must be clear, so controllers may ask a crew to use the full callsign if two similar ones are on frequency, and crews are trained to avoid confusion between similar callsigns.

Some typical sequences

Here is how a short arrival might sound, in simple form.

• Approach: "Delta one two three, descend and maintain four thousand."
• Pilot: "Descend and maintain four thousand, Delta one two three."
• Approach: "Delta one two three, turn left heading two seven zero, number two, follow the Airbus."
• Tower: "Delta one two three, runway two six, cleared to land, wind two seven zero at eight."

Each call is short, each has an instruction and each is read back. The "number two, follow" phrase tells the crew they are second in line and should keep a safe distance behind the aircraft ahead.

Phraseology in Short Final

The radio strip at the bottom of the game screen is built to follow these patterns. You will hear calls such as "cleared to land", "contact departure", "hold short" and "traffic alert, turn immediately", and the game reads its runway numbers the same way. The game also uses "mayday" and "pan-pan" for emergencies, the way real crews would.

The Short Final home page has the settings, and the game is simpler than the real thing. Callsigns are shortened, the weather is a summary, and the phrases cover only the situations that come up in the game. It is still a good place to hear the rhythm of a real frequency. Turn on radio chatter in the settings and listen to the calls for a few minutes before you play. Seattle-Tacoma, shown on its airport page with runways and a map, is a good airport to start with.

Differences between countries

Standard phraseology is set by ICAO, but each country adds rules and local habits. The United States, for example, often uses "position and hold" where other countries say "line up and wait". A call in one country can sound different in another, and a good pilot listens before speaking.

What to remember

• A call is made of who you are calling, who you are, and the message.
• "Roger" means received, and "wilco" means will comply. Neither means yes.
• Numbers are said one digit at a time, with "niner" for nine in most practice.
• Clearances are read back, and a correct readback ends with "readback correct".

Sources

• ICAO: the International Civil Aviation Organization, including the Manual of Radiotelephony (Doc 9432)
• FAA Air Traffic Control handbook, JO 7110.65 (phraseology in chapters 2 and 3)
• FAA Aeronautical Information Manual, chapter 4 (Radio Communications)
• SKYbrary: the aviation safety knowledge base