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.
The short answer
This AIM section is FAA advisory phraseology guidance stating that the three digits of a bearing, course, heading, or wind direction spoken on the radio should always be magnetic, and the word “true” must be added when it applies. It standardizes radio communication, supporting orderly operations under 14 CFR 91.183.
Research Notes
Common Questions
Are headings and courses on the radio magnetic or true?
Per AIM 4-2-10, bearing, course, heading, and wind direction should always be magnetic; the word “true” must be added when it applies. For example, a true course of 050 is spoken “zero five zero true,” while a magnetic heading of 100 is “heading one zero zero.”
How do you read a direction like 005 or 360 over the radio?
State the three separate digits. A magnetic course of 005 is “zero zero five,” and a magnetic bearing of 360 is “three six zero,” per the examples in AIM 4-2-10.
How is wind direction spoken?
As the three magnetic digits; AIM 4-2-10 gives a wind direction of 220 spoken as “wind two two zero.” This is advisory phraseology guidance, not a regulation.