ICAO Phonetic Alphabet

AIM ¶ 4-2-7 — ICAO Phonetic Alphabet

AIM 4-2-7 explains the ICAO phonetic alphabet for pilot-ATC radio communications, including when to use it and the full A-Z and 0-9 pronunciation table.

In Plain English

AIM 4-2-7 establishes the ICAO phonetic alphabet as the standard way pilots and controllers spell out letters and numbers over the radio. Plain English letters can sound alike on a noisy frequency (B, D, E, P, T, V), so substituting unambiguous words like Bravo, Delta, Echo, Papa, Tango, Victor prevents costly misunderstandings.

The AIM directs pilots to use the phonetic alphabet in these situations:

Initial contact with any ATC facility when stating your aircraft identification (e.g., "Cessna Six-One-Two-Tango-Charlie").
Adverse communications conditions when single letters, groups of letters, or difficult words need to be spelled out.
When ATC requests it because aircraft with similar-sounding call signs are on the same frequency.

Numbers also have standardized pronunciations — note "tree" for 3, "fife" for 5, "niner" for 9, and "zero" (never "oh"). These pronunciations reduce confusion with similar-sounding numerals, especially across languages and through static. While AIM 4-2-7 is a recommended practice rather than a regulation, fluent use of the phonetic alphabet is expected on every checkride and in everyday flying.

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AIM Source Text

FAA AIM ¶ 4-2-7

The International Civil Aviation Organization (ICAO) phonetic alphabet is used by FAA personnel when communications conditions are such that the information cannot be readily received without their use. ATC facilities may also request pilots to use phonetic letter equivalents when aircraft with similar sounding identifications are receiving communications on the same frequency. Pilots should use the phonetic alphabet when identifying their aircraft during initial contact with air traffic control facilities. Additionally, use the phonetic equivalents for single letters and to spell out groups of letters or difficult words during adverse communications conditions. (See TBL 4-2-2 .) TBL 4-2-2 Phonetic Alphabet/Morse Code

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Oral Exam Questions a DPE Might Ask

Q1When should a pilot use the ICAO phonetic alphabet on the radio?

Per AIM 4-2-7, pilots should use the phonetic alphabet when identifying their aircraft on initial contact with ATC, when spelling out single letters, groups of letters, or difficult words during adverse communications conditions, and whenever ATC requests it because of similar-sounding aircraft identifications on the same frequency.

Q2How are the numbers 3, 5, and 9 pronounced over the radio?

Per AIM 4-2-7, Table 4-2-2, three is pronounced "TREE," five is pronounced "FIFE," and nine is pronounced "NIN-ER." These pronunciations help distinguish numerals during noisy radio communications.

Q3What are the phonetic equivalents for the letters of your aircraft tail number, and why use them?

Per AIM 4-2-7, each letter has a standard ICAO word equivalent (e.g., A=Alfa, B=Bravo, C=Charlie, D=Delta, etc., per TBL 4-2-2). They are used because similar-sounding letters can be misunderstood under poor communications conditions, and pilots are expected to use them on initial ATC contact.

Related Paragraphs in Chapter 4

¶ 4-2-1

Pilot-Controller Communications

¶ 4-2-10

Radio Directions Phraseology

NORDO Tower Procedures

¶ 4-2-14