Section 7. Speed Adjustment
Keep speed adjustments to the minimum necessary to achieve or maintain required or desired spacing. Avoid adjustments requiring alternate decreases and increases. Permit pilots to resume normal speed when previously specified adjustments are no longer needed.
a. Consider the following when applying speed control:
1. Determine the interval required and the point at which the interval is to be accomplished.
2. Implement speed adjustment based on the following principles.
(a) Priority of speed adjustment instructions is determined by the relative speed and position of the aircraft involved and the spacing requirement.
(b) Speed adjustments are not achieved instantaneously. Aircraft configuration, altitudes, and speed determine the time and distance required to accomplish the adjustment.
3. Use the following techniques in speed control situations:
(a) Compensate for compression when assigning air speed adjustment in an in‐trail situation by using one of the following techniques:
(1) Reduce the trailing aircraft first.
(2) Increase the leading aircraft first.
(b) Assign a specific airspeed if required to maintain spacing.
(c) Allow increased time and distance to achieve speed adjustments in the following situations:
(1) Higher altitudes.
(2) Greater speed.
(3) Clean configurations.
(d) Ensure that aircraft are allowed to operate in a clean configuration as long as circumstances permit.
(e) Keep the number of speed adjustments per aircraft to the minimum required to achieve and maintain spacing.
b. Do not assign speed adjustment to aircraft:
1. At or above FL 390 without pilot consent.
2. Executing a published high altitude instrument approach procedure.
3. In a holding pattern.
4. Inside the final approach fix on final or a point 5 miles from the runway, whichever is closer to the runway.
c. At the time approach clearance is issued, previously issued speed adjustments must be restated if required.
d. Approach clearances cancel any previously assigned speed adjustment. Pilots are expected to make their own speed adjustments to complete the approach unless the adjustments are restated.
e. Express speed adjustments in terms of knots based on indicated airspeed (IAS) in 10-knot increments. At or above FL 240, speeds may be expressed in terms of Mach numbers in 0.01 increments for turbojet aircraft with Mach meters (i.e., Mach 0.69, 0.70, 0.71, etc.).
2. When assigning speeds to achieve spacing between aircraft at different altitudes, consider that ground speed may vary with altitude. Further speed adjustment may be necessary to attain the desired spacing.
a. Instruct aircraft to:
1. Maintain present/specific speed.
2. Maintain specified speed or greater/less.
3. Maintain the highest/lowest practical speed.
4. Increase or reduce to a specified speed or by a specified number of knots.
2. Speed restrictions of 250 knots do not apply to aircraft operating beyond 12 NM from the coastline within the U.S. Flight Information Region, in offshore Class E airspace below 10,000 feet MSL. However, in airspace underlying a Class B airspace area designated for an airport, or in a VFR corridor designated through such as a Class B airspace area, pilots are expected to comply with the 200 knot speed limit specified in 14 CFR Section 91.117(c). (See 14 CFR Sections 91.117(c) and 91.703.)
3. The phrases “maintain maximum forward speed” and “maintain slowest practical speed” are primarily intended for use when sequencing a group of aircraft. As the sequencing plan develops, it may be necessary to determine the specific speed and/or make specific speed assignments.
b. To obtain pilot concurrence for a speed adjustment at or above FL 390, as required by para 5-7-1, Application, use the following phraseology.
c. Simultaneous speed reduction and descent can be extremely difficult, particularly for turbojet aircraft. Specifying which action is to be accomplished first removes any doubt the pilot may have as to controller intent or priority. Specify which action is expected first when combining speed reduction with a descent clearance.
1. Speed reductions prior to descent.
2. Speed reduction following descent.
d. Specify combined speed/altitude fix crossing restrictions.
When assigning airspeeds, use the following recommended minima:
a. To aircraft operating between FL 280 and 10,000 feet, a speed not less than 250 knots or the equivalent Mach number.
2. If a pilot is unable to comply with the speed assignment, the pilot will advise.
b. When an operational advantage will be realized, speeds lower than the recommended minima may be applied.
c. To arrival aircraft operating below 10,000 feet:
1. Turbojet aircraft. A speed not less than 210 knots; except when the aircraft is within 20 flying miles of the runway threshold of the airport of intended landing, a speed not less than 170 knots.
2. Reciprocating engine and turboprop aircraft. A speed not less than 200 knots; except when the aircraft is within 20 flying miles of the runway threshold of the airport of intended landing, a speed not less than 150 knots.
1. Turbojet aircraft. A speed not less than 230 knots.
2. Reciprocating engine and turboprop aircraft. A speed not less than 150 knots.
e. Helicopters. A speed not less than 60 knots.
Advise aircraft when speed adjustment is no longer needed.