divide the airspeed by 10 and add one-half the result. For  example, at 100 knots, approximately 15° of bank is required  (100 ÷ 10 = 10 + 5 = 15); at 120 knots, approximately 18°  of bank is needed for a standard rate turn. On the roll-in, use the attitude indicator to establish  the approximate angle of bank, and then check the turn  coordinator’s miniature aircraft for a standard rate turn  indication or the aircraft’s turn-and-bank indicator. Maintain  the bank for this rate of turn, using the turn coordinator’s  miniature aircraft as the primary bank reference and the  attitude indicator as the supporting bank instrument.  [Figure 7-33] Note the exact angle of bank shown on  the banking scale of the attitude indicator when the turn  coordinator indicates a standard rate turn.  During the roll-in, check the altimeter, VSI, and attitude  indicator for the necessary pitch adjustments as the vertical  lift component decreases with an increase in bank. If constant  airspeed is to be maintained, the ASI becomes primary for  power, and the throttle must be adjusted as drag increases. As  the bank is established, trim off the pressures applied during  pitch and power changes.  To recover to straight-and-level flight, apply coordinated  aileron and rudder pressures opposite to the direction of  the turn. Strive for the same rate of roll-out used to roll into  the turn; fewer problems are encountered in estimating the  lead necessary for roll-out on exact headings, especially on  partial panel maneuvers. Upon initiation of the turn recovery,  the attitude indicator becomes the primary bank instrument.  When the airplane is approximately level, the heading  indicator is the primary bank instrument as in straight-and- level flight. Pitch, power, and trim adjustments are made as  changes in vertical lift component and airspeed occur. The  ball should be checked throughout the turn, especially if  control pressures are held rather than trimmed off.  Some airplanes are very stable during turns, requiring only  slight trim adjustments that permit hands-off flight while  the airplane remains in the established attitude. Other  airplanes require constant, rapid cross-check and control  during turns to correct overbanking tendencies. Due to the  interrelationship of pitch, bank, and airspeed deviations  during turns, cross-check must be fast in order to prevent  an accumulation of errors.  As long as an airplane is in a coordinated bank, it continues  to turn. Thus, the roll-out to a desired heading must be started  before the heading is reached. The amount of lead varies with  the relationship between the rate of turn, angle of bank, and  rate of recovery. For small heading changes, use a bank angle  that does not exceed the number of degrees to be turned. Lead  the desired heading by one-half the number of degrees of  bank used. For example, if a 10° bank is used during a change  in heading, start the roll-out 5 degrees before reaching the  desired heading. For larger changes in heading, the amount  Turns to Predetermined Headings 30.0  29.9  29.8  Primary bank initially supporting pitch Primary bank Supporting pitch Primary bank as turn is established Primary power Primary pitch Figure 7-33.  Standard rate turn, constant airspeed. 7-20