AIM DECODED

4-2-10. Directions

AIM Text

The three digits of bearing, course, heading, or wind direction should always be magnetic. The word “true” must be added when it applies.

Source: FAA Aeronautical Information Manual · current edition · paragraph 4-2-10.

Research Notes

AIM 4-2-10 covers phonetic alphabet pronunciation — the standardized phonetic alphabet used in all international and U.S. aviation comms.

The ICAO phonetic alphabet:

A — AlphaJ — JuliettS — Sierra
B — BravoK — KiloT — Tango
C — CharlieL — LimaU — Uniform
D — DeltaM — MikeV — Victor
E — EchoN — NovemberW — Whiskey
F — FoxtrotO — OscarX — X-ray
G — GolfP — PapaY — Yankee
H — HotelQ — QuebecZ — Zulu
I — IndiaR — Romeo

Digits: Zero ("zero"), one, two, three, four, five (sometimes "fife" internationally), six, seven, eight, niner. The "niner" is critical — it distinguishes from "five" on noisy channels and from the German "nein" in international ops.

Common errors:

  • "Jul-Ee-Et" vs "Joo-Lee-Et" — both heard, ICAO standard is "Joo-Lee-Et"
  • "Ex-Ray" not "X-Ray" pronounced
  • Pilots forget the phonetic and just say the letter — fine in casual conversation, problematic over noisy channels

Reference: AIM 4-2-10; ICAO Annex 10 Volume II (Radiotelephony Procedures).