Definition
The standard rate of turn used in instrument flying, equal to a heading change of 3 degrees every second. At this rate, an aircraft completes a 360-degree turn in two minutes, and a 180-degree turn in one minute. The turn coordinator and turn-and-slip indicator are calibrated so that a specific reference mark (the index or doghouse) shows when the aircraft is turning at this rate.
Plain English
A turn slow enough that the aircraft's heading changes by only 3 degrees each second. It is the standard turn rate pilots use when flying on instruments, and it always takes two minutes to go all the way around.
Context Anchor
Seen when using the turn coordinator to recognize or hold a standard-rate turn during instrument flying.
Derivation
Degree comes from an older word meaning “step.” In angle measurement, a degree is one small step around a circle. Second means a unit of time here, so 3 degrees per second means three small angle-steps of turn for each second that passes.
Why Pilots Care
Standard-rate turns keep maneuvers predictable, reduce workload in the cockpit, and are required for most holding patterns and instrument approach procedures.
Grounding Statement
If the airplane keeps turning at 3 degrees per second, it will point all the way around the compass and return to its original heading in two minutes.
Intuition Check
Do not read this as a 3-degree bank angle. It is not how much the airplane is tilted; it is how fast the airplane’s direction is changing.
Example Sentence 1
After being cleared to enter the hold, the pilot rolled into a standard-rate turn at 3 degrees per second to time the inbound leg.
Example Sentence 2
With the turn coordinator showing 3 degrees per second, the aircraft completed the 180-degree turn in one minute as planned.