AIM ¶ 4-2-10 — Radio Directions Phraseology

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.