AIM ¶ 4-2-10 — Radio Directions Phraseology
AIM 4-2-10: How pilots state bearings, courses, headings, and wind direction on the radio. Magnetic by default, 'true' when needed. Checkride prep.
In Plain English
When transmitting any direction over the radio — bearing, course, heading, or wind direction — speak the three digits individually and assume magnetic reference by default. Per AIM 4-2-10, you only add the word "true" when the value is referenced to true north (commonly seen in flight plans, oceanic operations, or when ATC specifies it).
Key points:
- Always say all three digits (e.g., 005 as "zero zero five")
- Default reference is magnetic — no qualifier needed
- Add "true" only when the direction is true, not magnetic
- Applies to courses, headings, bearings, and reported wind direction
Examples from the AIM:
- Magnetic course 005 → "zero zero five"
- True course 050 → "zero five zero true"
- Magnetic bearing 360 → "three six zero"
- Magnetic heading 100 → "heading one zero zero"
- Wind direction 220 → "wind two two zero"
This is recommended phraseology, not a regulation, but using it consistently prevents confusion with ATC and other traffic — particularly important because winds aloft forecasts are true while ATIS surface winds are magnetic.
AIM Source Text
FAA AIM ¶ 4-2-104-2-10. 4-2-10. Directions
The three digits of bearing, course, heading, or wind direction should always be magnetic. The word “true” must be added when it applies. EXAMPLE- (Magnetic course) 005 zero zero five (True course) 050 zero five zero true (Magnetic bearing) 360 three six zero (Magnetic heading) 100 heading one zero zero (Wind direction) 220 wind two two zero
Oral Exam Questions a DPE Might Ask
Q1When you state a heading or course on the radio, is it assumed to be magnetic or true?
Per AIM 4-2-10, the three digits of bearing, course, heading, or wind direction should always be magnetic. The word "true" must be added only when the direction is referenced to true north.
Q2How would you correctly say a magnetic course of 005 versus a true course of 050 on the radio?
Per AIM 4-2-10, magnetic course 005 is spoken as "zero zero five," and true course 050 is spoken as "zero five zero true" — adding the word "true" because the reference is not magnetic.
Q3How should wind direction be transmitted, and what reference does it use?
Per AIM 4-2-10, wind direction is given using all three digits and is assumed magnetic. For example, a wind direction of 220 is stated as "wind two two zero."
Related Paragraphs in AIM Chapter 4