Turn Coordinator

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The bank attitude of an aircraft in coordinated flight is shown indirectly on the heading indicator, since banking results in a turn and change in heading. Assuming the same airspeed in both instances, a rapid movement of the heading indicator needle (or azimuth card in a directional gyro) indicates a large angle of bank, whereas a slow movement of the needle or card reflects a small angle of bank. If you note the rate of movement of the heading indicator and compare it to the attitude indicator’s degrees of bank, you will learn to look for important bank information on the heading indicator. This is especially the case when the attitude indicator’s precession error makes a precise check of heading information necessary in order to maintain straight flight.

When you note deviations from straight flight on the heading indicator, make your correction to the desired heading using a bank angle no greater than the number of degrees to be turned. In any case, limit your bank corrections to a bank angle no greater than that required for a standard-rate turn. Use of larger bank angles requires a very high level of proficiency, and normally results in overcontrolling and erratic bank control.