Standard Rate Turn
A standard rate turn is a turn in which an airplane completes a 360 degree turn in 2 minutes. This is done by have a turn of 3 degrees per second. If the airplane is moving faster then 250 knots then a standard rate turn is 1.5 degrees per second or a 360-degree turn in 4 minutes. Every airplane must be able to complete a standard rate turn in order to be certified.
True airspeed is directly related to a standard rate turn. If you are traveling at a faster speed then you are going to need a steeper bank in order to accomplish the 3-degree per second requirement. To accomplish a standard rate turn pilots use either a turn coordinator or a turn and bank indicator. There is a marking on the instrument that points to standard rate and allows the pilot some ease when flying in instrument conditions and there is a clock so the pilot can time himself to make sure his turn is on point. On lighter aircraft there is a 2-minute turn indicator so assist the pilots. To figure out the amount of bank needed in order to accomplish a standard rate turn we have the equation:
where: TAS = true airspeed
Standard rate turns are used as commonality in almost all instrument procedures and when pilots go to be instrument certified they must be able to perform a standard rate turn for the check pilot. Holding, intercepting, tracking, approaches, departures, and vectors are all accomplished using standard rate turns.