Aviation Phonetic Alphabet & How to Say Numbers

Why pilots say "niner" and "tree," the full alphabet you need automatic, and exactly how numbers, headings, altitudes, and frequencies are spoken. · 6 min read

Radios are noisy, and a lot of letters sound identical through static — B, D, P, T, V, and E are nearly impossible to tell apart when the signal is weak. To fix that, aviation (and the military, and shipping) uses a phonetic alphabet: a distinct, unmistakable word for each letter. A few numbers also get special pronunciations for the same reason. None of this is hard, but all of it needs to be instant — you should never have to stop and think "what is the word for K?" while you are also flying an airplane. This guide covers the full alphabet, the numbers, and the specific ways headings, altitudes, frequencies, and squawk codes are spoken.

The phonetic alphabet

Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliet, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.

You will use these constantly for your callsign, for taxiway identifiers ("taxi via Alpha, Bravo"), for ATIS codes ("Information Quebec"), and for spelling anything unusual. A tip for learning them fast: attach each to a vivid image, and practice spelling out signs and license plates you see during the day.

The numbers that change

Most numbers are said normally, but three are altered so they cannot be confused with each other or with common words:

3 is spoken "tree" — so the "th" does not get clipped or lost in static
5 is spoken "fife" — so it does not sound like "fire" or blur into "nine"
9 is spoken "niner" — so it does not sound like "five" or the German "nein"
0 is "zero" (not "oh"), and the decimal point in a frequency is spoken as the word "point"

Numbers are spoken digit-by-digit

This is the rule new pilots most often miss: on the radio you almost always say numbers one digit at a time, not as whole numbers. A frequency of 124.35 is "one two four point tree fife," not "one twenty-four thirty-five." A squawk code of 4271 is "four two seven one." This keeps every digit distinct.

Headings and altitudes

Headings are three digits, spoken individually: heading 070 is "heading zero seven zero"; heading 290 is "heading two niner zero."
Altitudes below 18,000 ft are spoken as thousands and hundreds: 4,500 is "four thousand five hundred"; 12,000 is "one two thousand" (or "twelve thousand").
A frequency: "contact Departure on one two one point tree."

🎙 You say “Skyhawk Five-Two-Kilo, heading zero seven zero, climbing four thousand five hundred.”

Callsign phonetic, heading digit-by-digit, altitude in thousands/hundreds.

Common mistakes

Saying "twenty-four thirty-five" for a frequency instead of digit-by-digit.
Using "oh" for zero — say "zero."
Reverting to plain "three, five, nine" when rushed. Under pressure is exactly when "tree, fife, niner" earns its keep.

💡 ATCpal has a 30-second phonetic speed game that drills Alpha-Bravo-Charlie and tree-fife-niner until they are reflexive — no mic needed, and free at atcpal.app. It is the fastest way to make the alphabet automatic.

Phraseology sourced from the FAA Aeronautical Information Manual (Change 3, effective 9 July 2026) and the Pilot/Controller Glossary. Check the AIM · Last reviewed 13 August 2026.

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