indicator, and make the necessary adjustments. After you have made this change, again check the altimeter and vertical speed indicator to determine whether or not the correction was adequate. used, the rate of cross-check must be increased as you reduce power. As the helicopter decelerates, check the altimeter and VSI for needed pitch changes, and the bank instruments for needed bank changes. If the needle of the turn-and-slip indicator shows a deviation from the desired deflection, change the bank. Adjust pitch attitude to maintain altitude. When the airspeed approaches that desired, the airspeed indicator becomes primary for power control. Adjust the torque meter to maintain the desired airspeed. Use pedal trim to ensure the maneuver is coordinated. Until your control technique is very smooth, frequently cross-check the attitude indicator to keep from over- controlling and to provide approximate bank angles appropriate for the changing airspeeds.  For climbing and descending turns, the techniques described earlier for straight climbs and descents and those for standard rate turns are combined. For practice, start the climb or descent and turn simultaneously. The primary and supporting instruments for a stabilized con- stant airspeed left climbing turn are illustrated in figure 12-21. The leveloff from a climbing or descending turn is the same as the leveloff from a straight climb or descent. To recover to straight-and-level flight, you may stop the turn and then level off, level off and then stop the turn, or simultaneously level off and stop the turn. During climbing and descending turns, keep the ball of the turn indicator centered with pedal trim. The use of gyroscopic heading indicators make head- ing control very easy. However, if the heading indica- tor fails or your helicopter does not have one installed, you must use the magnetic compass for heading refer- ence. When making compass-only turns, you need to adjust for the lead or lag created by acceleration and deceleration errors so that you roll out on the desired heading. When turning to a heading of north, the lead for the roll-out must include the number of degrees of your latitude plus the lead you normally use in recov- ery from turns. During a turn to a south heading, main- tain the turn until the compass passes south the number A turn using 30° of bank is seldom necessary, or advis- able, in IMC, but it is an excellent maneuver to increase your ability to react quickly and smoothly to rapid changes of attitude. Even though the entry and recov- ery technique are the same as for any other turn, you will probably find it more difficult to control pitch because of the decrease in vertical lift as the bank increases. Also, because of the decrease in vertical lift, there is a tendency to lose altitude and/or airspeed. Therefore, to maintain a constant altitude and airspeed, additional power is required. You should not initiate a correction, however, until the instruments indicate the need for a correction. During the maneuver, note the need for a correction on the altimeter and vertical speed indicator, then check the indications on the attitude 12-17 Figure 12-21. Flight instrument indications for a stabilized left climbing turn at a constant airspeed. COMPASS TURNS 30° BANK TURN CLIMBING AND DESCENDING TURNS 40 50 60 70 80 90 100 110 120 0 10 20 30 TORQUE PERCENT GLYPH<.notdef> Primar yGLYPH<.notdef> PowerGLYPH<.notdef> GLYPH<.notdef> Supporting Pitc hGLYPH<.notdef> and Bank Primary Bank Primary Pitch Supporting Pitch