AIM ¶ 5-5-9 — ATC Speed Adjustments
AIM 5-5-9 explains pilot and controller responsibilities for ATC speed adjustments, tolerances, and phraseology like 'resume normal speed' for checkride prep.
In Plain English
AIM 5-5-9 outlines how ATC speed adjustments work and who is responsible for what. As the pilot, you must:
- Advise ATC any time cruising airspeed varies ±5% or 10 knots (whichever is greater) from your filed flight plan.
- Comply with assigned speeds, holding within ±10 knots or 0.02 Mach of the assigned value.
- Tell ATC if the assigned speed is unsafe or outside your aircraft's operating specs — it's your prerogative to refuse.
- When descending through 10,000 feet MSL after an assigned speed above 250 KIAS, comply with 14 CFR 91.117(a) (250 knot limit below 10,000).
Controllers, in turn, won't use speed adjustments as a substitute for good vectoring, will assign speeds in 5-knot increments, and won't require constant speed-up/slow-down changes. They terminate assignments using specific phraseology you should know:
- "Resume normal speed" — no published restrictions apply.
- "Comply with speed restrictions" — rejoining a procedure with published speeds.
- "Resume published speed" — cleared on a procedure with published speeds.
- "Delete speed restrictions" — published restrictions no longer required.
Note: "Climb via SID" requires compliance with all published altitude and speed restrictions. Above FL390, ATC won't assign speed adjustments without your consent. This is AIM guidance (informational), but the underlying speed regulations in 14 CFR 91.117 are mandatory.
AIM Source Text
FAA AIM ¶ 5-5-95-5-9. 5-5-9. Speed Adjustments
Pilot. Advises ATC any time cruising airspeed varies plus or minus 5 percent or 10 knots, whichever is greater, from that given in the flight plan. Complies with speed adjustments from ATC unless: The minimum or maximum safe airspeed for any particular operation is greater or less than the requested airspeed. In such cases, advises ATC. NOTE- It is the pilot's responsibility and prerogative to refuse speed adjustments considered excessive or contrary to the aircraft's operating specifications. Operating at or above 10,000 feet MSL on an ATC assigned SPEED ADJUSTMENT of more than 250 knots IAS and subsequent clearance is received for descent below 10,000 feet MSL. In such cases, pilots are expected to comply with 14 CFR section 91.117(a). When complying with speed adjustment assignments, maintains an indicated airspeed within plus or minus 10 knots or 0.02 Mach number of the specified speed. Controller. Assigns speed adjustments to aircraft when necessary but not as a substitute for good vectoring technique. Adheres to the restrictions published in FAA Order JO 7110.65, Air Traffic Control, as to when speed adjustment procedures may be applied. Avoids speed adjustments requiring alternate decreases and increases. Assigns speed adjustments to a specified IAS (KNOTS)/Mach number or to increase or decrease speed using increments of 5 knots or multiples thereof. Terminates ATC-assigned speed adjustments when no longer required by issuing further instructions to pilots in the following manner: Advises pilots to “resume normal speed” when the aircraft is on a heading, random routing, charted procedure, or route without published speed restrictions. Instructs pilots to “comply with speed restrictions” when the aircraft is joining or resuming a charted procedure or route with published speed restrictions. CAUTION- The phraseology “Climb via SID” requires compliance with all altitude and/or speed restrictions depicted on the procedure. Instructs pilots to “resume published speed” when aircraft are cleared via a charted instrument flight procedure that contains published speed restrictions. Advises aircraft to “delete speed restrictions” when ATC assigned or published speed restrictions on a charted procedure are no longer required. Clears pilots for approach without restating previously issued speed adjustments. REFERENCE- Pilot/Controller Glossary Term - Resume Normal Speed. Pilot/Controller Glossary Term - Resume Published Speed. Gives due consideration to aircraft capabilities to reduce speed while descending. Does not assign speed adjustments to aircraft at or above FL 390 without pilot consent.
Oral Exam Questions a DPE Might Ask
Q1When must you advise ATC of a change in your cruising airspeed?
Per AIM 5-5-9, you must advise ATC any time your cruising airspeed varies plus or minus 5 percent or 10 knots, whichever is greater, from the airspeed given in your flight plan.
Q2What tolerance must you maintain when complying with an ATC speed adjustment, and can you refuse one?
Per AIM 5-5-9, you must maintain an indicated airspeed within ±10 knots or 0.02 Mach of the assigned speed. It is the pilot's responsibility and prerogative to refuse a speed adjustment that is excessive, unsafe, or contrary to the aircraft's operating specifications — you must advise ATC in that case.
Q3What does ATC mean by 'resume normal speed' versus 'resume published speed'?
Per AIM 5-5-9, 'resume normal speed' is used when the aircraft is on a heading, random routing, or a route without published speed restrictions. 'Resume published speed' is used when the aircraft is cleared via a charted instrument flight procedure that contains published speed restrictions.
Related Paragraphs in AIM Chapter 5