4-2-11 Speeds
AIM Chapter 4. Air Traffic Control — Section 4-2, Radio Communications Phraseology
Official text — AIM 4-2-11
AIM — FAA OPERATIONAL GUIDANCEThe separate digits of the speed followed by the word “KNOTS.” Except, controllers may omit the word “KNOTS” when using speed adjustment procedures; e.g., “REDUCE/INCREASE SPEED TO TWO FIVE ZERO.”
EXAMPLE— (Speed) 250 two five zero knots (Speed) 190 one niner zero knots
The separate digits of the Mach Number preceded by “Mach.”
EXAMPLE— (Mach number) 1.5 Mach one point five (Mach number) 0.64 Mach point six four (Mach number) 0.7 Mach point seven
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.