increase in power is required to maintain airspeed, slight forward cyclic pressure may be required since the heli- copter tends to pitch up as collective pitch angle is increased. Apply pedal trim, as required, to keep the ball centered.  You use the same cross-check and control technique in making timed turns that you use to make turns to a pre- determined heading, except that you substitute the clock for the heading indicator. The needle of the turn- and-slip indicator is primary for bank control, the altimeter is primary for pitch control, and the airspeed indicator is primary for power control. Begin the roll-in when the clock’s second hand passes a cardinal point, hold the turn at the calibrated standard-rate indication, or half-standard-rate for small changes in heading, and begin the roll-out when the computed number of sec- onds has elapsed. If the roll-in and roll-out rates are the same, the time taken during entry and recovery need not be considered in the time computation. To recover to straight-and-level flight, apply cyclic in the direction opposite the turn. The rate of roll-out should be the same as the rate used when rolling into the turn. As you initiate the turn recover, the attitude indicator becomes primary for bank. When the helicop- ter is approximately level, the heading indicator becomes primary for bank as in straight-and-level flight. Cross-check the airspeed indicator and ball closely to maintain the desired airspeed and pedal trim. If you practice timed turns with a full instrument panel, check the heading indicator for the accuracy of your turns. If you execute the turns without the heading indi- cator, use the magnetic compass at the completion of the turn to check turn accuracy, taking compass devia- tion errors into consideration.  A helicopter turns as long as its lateral axis is tilted; there- fore, the recovery must start before the desired heading is reached. The amount of lead varies with the rate of turn and your piloting technique.  As a guide, when making a 3° per second rate of turn, use a lead of one-half the bank angle. For example, if you are using a 12° bank angle, use half of that, or 6°, as the lead point prior to your desired heading. Use this lead until you are able to determine the exact amount required by your particular technique. The bank angle should never exceed the number of degrees to be turned. As in any standard rate turn, the rate of recov- ery should be the same as the rate for entry. During turns to predetermined headings, cross-check the pri- mary and supporting pitch, bank, and power instru- ments closely. Changing airspeed in turns is an effective maneuver for increasing your proficiency in all three basic instru- ment skills. Since the maneuver involves simultaneous changes in all components of control, proper execution requires a rapid cross-check and interpretation, as well as smooth control. Proficiency in the maneuver also contributes to your confidence in the instruments dur- ing attitude and power changes involved in more com- plex maneuvers. A timed turn is a turn in which the clock and turn-and- slip indicator are used to change heading a definite number of degrees in a given time. For example, using a standard rate turn, a helicopter turns 45° in 15 sec- onds. Using a half-standard rate turn, the helicopter turns 45° in 30 seconds. Timed turns can be used if your heading indicator becomes inoperative. Pitch and power control techniques are the same as those used during airspeed changes in straight-and- level flight. As discussed previously, the angle of bank necessary for a given rate of turn is proportional to the true airspeed. Since the turns are executed at standard rate, the angle of bank must be varied in direct pro- portion to the airspeed change in order to maintain a constant rate of turn. During a reduction of airspeed, you must decrease the angle of bank and increase the pitch attitude to maintain altitude and a standard rate turn.  Prior to performing timed turns, the turn coordinator should be calibrated to determine the accuracy of its indications. To do this, establish a standard rate turn by referring to the turn-and-slip indicator. Then as the sweep second hand of the clock passes a cardinal point (12, 3, 6, or 9), check the heading on the heading indi- cator. While holding the indicated rate of turn constant, note the heading changes at 10-second intervals. If the helicopter turns more or less than 30° in that interval, a smaller or larger deflection of the needle is necessary to produce a standard rate turn. When you have cali- brated the turn-and-slip indicator during turns in each direction, note the corrected deflections, if any, and apply them during all timed turns. The altimeter and the needle on the turn indicator should remain constant throughout the turn. The altimeter is primary for pitch control, and the turn nee- dle is primary for bank control. The torque meter is primary for power control while the airspeed is chang- ing. As the airspeed approaches the new indication, the airspeed indicator becomes primary for power control.  Two methods of changing airspeed in turns may be used. In the first method, airspeed is changed after the turn is established. In the second method, the airspeed change is initiated simultaneously with the turn entry. The first method is easier, but regardless of the method 12-16 TIMED TURNS TURNS TO A PREDETERMINED HEADING CHANGE OF AIRSPEED IN TURNS