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Alpha, Bravo, Charlie, pay attention… Alpha, Bravo, Charlie! You may not know exactly what this means, but you’ve certainly come across someone uttering those words in a war movie or series. It is even likely that whoever said such a phrase would be an airplane or a helicopter pilot. This type of communication is nothing more than an exchange of messages through the international phonetic alphabet.
Very common practice in civil and private aviation, as well as in the military environment. The aim is simple: to make communication via radio or telephone, often unstable in these media, more assertive.
Just think of the proximity of some letters such as “p” and “b”, “n” and “m” or “f” and “s” to imagine the difficulty of transmitting the message in case of interference or excessive noise. It’s the same principle as when you, making a registration by telephone, spell out to the attendant: “M for Maria, A for Amor, C for Casa, D for Dado…”.
Although known as the phonetic alphabet, the system is actually a spelling alphabet. The official name is International Radiotelephony Spelling Alphabet, but it is also known globally by the phonetic or spelling alphabet of the International Civil Aviation Organization (ICAO) or the North Atlantic Treaty Organization (NATO). In Brazil, it is also called by the “Zulu” alphabet or aeronautical alphabet.
The phonetic alphabet
Check how each letter is pronounced when using the phonetic alphabet in aviation:
| Símbolo | Código | Morse Code | Phonic (pronunciation) |
|---|---|---|---|
| A | Alfa/Alpha | ● ▬ | AL FAH |
| B | Bravo | ▬ ● ● ● | BRAH VOH |
| C | Charlie | ▬ ● ▬ ● | CHAR LEE |
| D | Delta | ▬ ● ● | DELL TAH |
| E | Echo | .● | ECK OH |
| F | Foxtrot | ● ● ▬ ● | FOKS TROT |
| G | Golf | ▬ ▬ ● | GOLF |
| H | Hotel | ● ● ● ● | HOH TELL |
| I | India | ● ● | IN DEE AH |
| J | Juliett | ● ▬ ▬ ▬ | JEW LEE ETT |
| K | Kilo | ▬ ● ▬ | KEY LOH |
| L | Lima | ● ▬ ● ● | LEE MAH |
| M | Mike | ▬ ▬ | MIKE |
| N | November | ▬ ● | NO VEMBER |
| O | Oscar | ▬ ▬ ▬ | OSS CAH |
| P | Papa | ● ▬ ▬ ● | PAH PAH |
| Q | Quebec | ▬ ▬ ● ▬ | KEH BECK |
| R | Romeo | ● ▬ ● | ROW ME OH |
| S | Sierra | ● ● ● | SEE AIRRAH |
| T | Tango | ▬ | TANG OH |
| U | Uniform | ● ● ▬ | YOU NEE FORM |
| V | Victor | ● ● ● ▬ | VIK TAH |
| W | Whiskey | ● ▬ ▬ | WISS KEY |
| X | X-ray | ▬ ● ● ▬ | ECKS RAY |
| Y | Yankee | ▬ ▬ ● ● | YANG KEY |
| Z | Zulu | ▬ ▬ ▬ ▬ ▬ | ZOO LOO |
Aviation use
The phonetic alphabet in private aviation serves to help flight towers, control teams, helicopter and jet pilots share information quickly, concisely and accurately.
For example, the pilot of a private jet may inform the fixed-base operator or aerodrome management, in advance, of the approximate time of his arrival, how long he will remain at the location, what services are required by passengers or crew, the tail number of the aircraft etc.
In the case of a larger airport, the alphabet will be useful to receive transmissions from the Automatic Terminal Information Service (ATIS), which continuously updates essential data such as available routes, free runways and the weather.
If your plane’s prefix is, for example, PR-XMA, the pilot will inform the interlocutors: Papa Romeo X-ray Mike Alfa. This will eliminate the chance that the other person will understand BR or TR.
As for the transmission of the squawk – a transponder code to inform the traffic control of the aircraft’s identification – combinations of four numbers are used and the numbers also have a special pronunciation. According to the International Civil Aviation Organization, the numbers should be pronounced as:
Zero, Wun, Too, Tree, Fower, Fife, Six, Seven, Ait, Niner.
Historic
As mentioned, phonetic alphabets are systems that represent the sound emission of languages, in a standard way, most used by linguistic researchers. The history of “spelling” alphabets, which we conventionally call the phonetic alphabet in aviation, dates back to the beginning of the 20th century.
The first initiatives opted for the use of the name of cities – there were those who defined from Argentina to Zanzibar, as well as those who went from Amsterdam to Zurich. Before World War II, different countries and institutions were using their own versions.
During the global conflict, however, the first unification movements began. At that time, the United States used the “Able Baker” alphabet (which had those words in the first two letters). From this system, there are still some words left today, such as Charlie, Mike and Victor. To alleviate communication confusion, the Allies (UK, Australia, etc.) have chosen to follow this same model.
After the war, the US Army asked the Psychoacoustics Laboratory at Harvard University to conduct a search to find the most suitable words to represent the different letters, taking into account that they would be pronounced on military radio sets and in the midst of intense noise.
Using several common alphabets, this work resulted in the basis of what is now considered the international aviation phonetic alphabet, as standardized by NATO. Before the final version, however, throughout the 1940s and 1950s, the alphabet underwent several changes.
First, to extend usage beyond English-speaking nations, as “Able Baker” had words that resonated better in English. Then, reviews started to consider how the pronunciation would also be done in French, Spanish and Portuguese. The final version, as we know it today, was defined in 1956, with publication by Icao and adoption by NATO.