If an antitorque or collective servo fails, you might be able to continue to the next suitable landing site.  Both straight-ahead and turning autorotations should be practiced by reference to instruments. This training will ensure that you can take prompt corrective action to maintain positive aircraft control in the event of an engine failure.  This maneuver should only be performed as part of your training for an instrument rating. The procedures and techniques described here should be modified, as necessary, to conform with those set forth in the operat- ing instructions for the particular helicopter being flown. To enter autorotation, reduce collective pitch smoothly to maintain a safe rotor r.p.m. and apply pedal trim to keep the ball of the turn-and-slip indicator centered. The pitch attitude of the helicopter should be approxi- mately level as shown by the attitude indicator. The  airspeed indicator is the primary pitch instrument and should be adjusted to the recommended autorotation speed. The heading indicator is primary for bank in a straight-ahead autorotation. In a turning autorotation, a standard rate turn should be maintained by reference to the needle of the turn-and-slip indicator. Adjust the miniature aircraft in the attitude indicator, as appropriate, for the aircraft being flown. After the helicopter is aligned with the runway or takeoff pad, to prevent forward movement of a helicopter equipped with a wheel-type landing gear, set the parking brake or apply the toe brakes. If the parking brake is used, it must be unlocked after the takeoff has been completed. Apply sufficient friction to the collective pitch control to minimize overcontrolling and to prevent creeping. Excessive friction should be avoided since this limits collective pitch movement. After checking all instruments for proper indications, start the takeoff by applying collective pitch and a prede- termined power setting. Add power smoothly and steadily to gain airspeed and altitude simultaneously and to prevent settling to the ground. As power is applied and the helicopter becomes airborne, use the antitorque ped- als initially to maintain the desired heading. At the same time, apply forward cyclic to begin accelerating to climbing airspeed. During the initial acceleration, the pitch attitude of the helicopter, as read on the attitude indicator, should be one to two bar widths low. The pri- mary and supporting instruments after becoming airborne are illustrated in figure 12-22.  As the airspeed increases Most helicopters certified for single-pilot IFR flight are required to have autopilots, which greatly reduces pilot workload. If an autopilot servo fails, however, you have to resume manual control of the helicopter. How much your workload increases, depends on which servo fails. If a cyclic servo fails, you may want to land immediately as the workload increases tremendously. 12-19 Figure 12-22. Flight instrument indications during an instrument takeoff. COMMON ERRORS DURING AUTOROTATIONS SERVO FAILURE INSTRUMENT TAKEOFF AUTOROTATIONS 1. Uncoordinated entry due to improper pedal trim. 2. Poor airspeed control due to improper pitch attitude. 3. Poor heading control in straight-ahead autorotations. 4. Failure to maintain proper rotor r.p.m. 5. Failure to maintain a standard rate turn during turn- ing autorotations.  40 50 60 70 80 90 100 110 120 0 10 20 30 TORQUE PERCENT GLYPH<.notdef> PrimaryGLYPH<.notdef> PowerGLYPH<.notdef> GLYPH<.notdef> Primary PitchGLYPH<.notdef> Supporting Bank Supporting Pitch Supporting Bank Supporting Pitch Supporting Pitch Primary Bank