Issuing Speed Instructions

In this lesson we are going to talk about issuing speed instructions. Do not issue Speed Instructions as a substitute for good vectoring. Remember that vectoring should be for sequencing, and speed instructions should be used for spacing.


When assigning a speed, there are five key points to remember:

• Approach clearance cancels any assigned speed adjustment unless you reissue it.

• Groundspeed shown in the aircraft’s data block will often be higher than the indicated airspeed the pilot reports.

• Speed adjustments don’t happen immediately. Different factors all combine to affect the time needed to change an aircraft’s speed.

• The pilot may refuse any speed adjustment in the interest of safety.

• Aircraft assigned a speed greater than 250 knots above 10,000 MSL will automatically reduce to 250 knots or less when descending through 10,000 MSL.

Speed Restrictions Issuance

You may not assign a speed adjustment to an aircraft:

• On a High Altitude Instrument Approach Procedure.

• In a holding pattern. (Do not confuse this with advising the pilot of the Maximum Holding Speed)

• Inside the final approach fix.

Methods For Issuing Speed Instructions

There are four different ways to adjust an aircraft's speed:

• Have it maintain a specific speed: "MAINTAIN (number) KNOTS" , e.g. "Maintain 250 knots."

• Have it maintain higher or lower than a specified speed: "MAINTAIN (number) KNOTS OR GREATER" or "DO NOT EXCEED (number) KNOTS", e.g. "Maintain 170 knots or greater" or "Do not exceed 170 knots"

• Have it maintain the highest or lowest practical speed: "MAINTAIN MAXIMUM FORWARD SPEED" or "MAINTAIN SLOWEST PRACTICAL SPEED"

• Have it increase or decrease by a specified number of knots: "REDUCE SPEED (number) KNOTS", e.g. "Reduce speed 20 knots"

If you want an aircraft to descend and make a speed adjustment you must tell it which one to do first: "(speed instruction) THEN (altitude instruction)", e.g "MAINTAIN 210 KNOTS THEN DESCEND AND MAINTAIN 7,000"
As soon as speed adjustments are no longer needed inform the pilot: "RESUME NORMAL SPEED"

Final Points to Consider

• Arriving jet aircraft below 10,000 MSL may not be reduced below 210 knots except when within 20 flying miles of the runway where they may be reduced to 170 knots.

• Departing jet aircraft may not be assigned a speed less than 230 knots.

• Arriving propeller aircraft below 10,000 MSL may not be reduced below 200 knots except when within 20 flying miles of the runway where they may be reduced to 150 knots.

• Departing propeller aircraft may not be assigned a speed less than 150 knots.

• Helicopters may not be assigned a speed of less than 60 knots at any time.

NEXT: Uncontrolled Field Operations

PREVIOUS: Issuing Holding Instructions

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