Radio language

[HACKWORTH]

A FAR/AIM general aviation question.

I hear lots of people use “Tree” instead of three like I’m sure they were instructed (for example)

The most common of course in “niner”, but the others are used less often.

Is it specified in the AIM or FAR that this type of speaking should be used? If so, where?

Thanks.

[Keith Smith]

Secton 4-2-7 of the AIM. If you're ever in doubt, open up the PDF and search for 'fife'. Easily found.

[HACKWORTH]

Excellent!

Thanks.

So as I understand it, it is the recommended way of speaking, but if I decided to say "Three", I am not breaking a FAR, correct?