30.0  29.9  29.8  Primary pitch Supporting pitch and bank Supporting bank Primary bank Supporting pitch Primary power as airspeed approaches desired value Figure 7-29.  Level off at cruising speed. The following method for entering descents is effective  with or without an attitude indicator. First, reduce airspeed  to a selected descent airspeed while maintaining straight- and-level flight, then make a further reduction in power  (to a predetermined setting). As the power is adjusted,  simultaneously lower the nose to maintain constant airspeed,  and trim off control pressures.  During a constant airspeed descent, any deviation from the  desired airspeed calls for a pitch adjustment. For a constant  rate descent, the entry is the same, but the VSI is primary for  pitch control (after it stabilizes near the desired rate), and the  ASI is primary for power control. Pitch and power must be  closely coordinated when corrections are made, as they are  in climbs.  [Figure 7-30]  The level off from a descent must be started before reaching  the desired altitude. The amount of lead depends upon the  rate of descent and control technique. With too little lead,  the airplane tends to overshoot the selected altitude unless  technique is rapid. Assuming a 500 fpm rate of descent, lead  the altitude by 100–150 feet for a level off at an airspeed  higher than descending speed. At the lead point, add power to  the appropriate level flight cruise setting.  [Figure 7-31]  Since  the nose tends to rise as the airspeed increases, hold  forward elevator pressure to maintain the vertical speed at  the descending rate until approximately 50 feet above the  altitude, and then smoothly adjust the pitch attitude to the  level flight attitude for the airspeed selected.  To level off from a descent at descent airspeed, lead the  desired altitude by approximately 50 feet, simultaneously  adjusting the pitch attitude to level flight and adding power to  a setting that holds the airspeed constant.  [Figure 7-32]  Trim  off the control pressures and continue with the normal  straight-and-level flight cross-check.  Common errors result from the following faults: Common Errors in Straight Climbs and Descents Entry Leveling Off 1.  Overcontrolling pitch on climb entry. Until the pitch  attitudes related to specific power settings used in  climbs and descents are known, larger than necessary  pitch adjustments are made. One of the most difficult  habits to acquire during instrument training is to  restrain the impulse to disturb a flight attitude until  the result is known. Overcome the inclination to  make a large control movement for a pitch change,  and learn to apply small control pressures smoothly,  cross-checking rapidly for the results of the change,  and continuing with the pressures as instruments show  the desired results. Small pitch changes can be easily  controlled, stopped, and corrected; large changes are  more difficult to control.  7-17