4-2-8 Figures
AIM Chapter 4. Air Traffic Control — Section 4-2, Radio Communications Phraseology
Official text — AIM 4-2-8
AIM — FAA OPERATIONAL GUIDANCEa. Figures indicating hundreds and thousands in round number, as for ceiling heights, and upper wind levels up to 9,900 must be spoken in accordance with the following.
EXAMPLE— 1. 500 five hundred
2. 4,500 four thousand five hundred
b. Numbers above 9,900 must be spoken by separating the digits preceding the word “thousand.”
EXAMPLE— 1. 10,000 one zero thousand
2. 13,500 one three thousand five hundred
c. Transmit airway or jet route numbers as follows.
EXAMPLE— 1. V12 Victor Twelve
2. J533 J Five Thirty-Three
d. All other numbers must be transmitted by pronouncing each digit.
EXAMPLE— 10 one zero
e. When a radio frequency contains a decimal point, the decimal point is spoken as “POINT.”
EXAMPLE— 122.1 one two two point one
NOTE— ICAO procedures require the decimal point be spoken as “DECIMAL.” The FAA will honor such usage by military aircraft and all other aircraft required to use ICAO procedures.
Reproduced from the FAA Aeronautical Information Manual (Basic (with Change 3)). The AIM is FAA guidance, not regulation. Verify against the official source before relying on it operationally.
Is this a regulation?
No — this is FAA guidance, not a regulation.
Aeronautical Information Manual. FAA operational guidance and recommended practices. The AIM is not regulatory, although it often explains how to comply with regulations.