1 2 3 4 5 Figure 10-3.  Rapid deceleration or quick stop.  Common Errors Steep Approach between 25 and 40 feet, depending upon the manufacturer’s  recommendations, accelerate to the desired entry speed,  which is approximately 45 knots for most training helicopters  (position 2). The altitude chosen should be high enough to  avoid danger to the tail rotor during the flare, but low enough  to stay out of the hazardous areas of that helicopter’s height- velocity diagram throughout the maneuver. In addition, this  altitude should be low enough that the helicopter can be  brought to a hover during the recovery. At position 3, initiate the deceleration by applying aft cyclic  to reduce forward groundspeed. Simultaneously, lower the  collective, as necessary, to counteract any climbing tendency.  The timing must be exact. If too little collective is taken out  for the amount of aft cyclic applied, the helicopter climbs. If  too much downward collective is applied, the helicopter will  descend. A rapid application of aft cyclic requires an equally  rapid application of down collective. As collective is lowered,  apply proper antitorque pedal pressure to maintain heading,  and adjust the throttle to maintain rpm. The G loading on the  rotor system depends on the pitch-up attitude. If the attitude is  too high, the rotor system may stall and cause the helicopter  to impact the surface. After attaining the desired speed (position 4), initiate the  recovery by lowering the nose and allowing the helicopter  to descend to a normal hovering height in level flight and  zero groundspeed (position 5). During the recovery, increase  collective pitch, as necessary, to stop the helicopter at normal  hovering height, adjust the throttle to maintain rpm, and apply  proper antitorque pedal pressure, as necessary, to maintain  heading. During the maneuver, visualize rotating about the  tail rotor’s horizontal axis until a normal hovering height is  reached. A steep approach is used primarily when there are obstacles  in the approach path that are too high to allow a normal  approach. A steep approach permits entry into most confined  areas and is sometimes used to avoid areas of turbulence  around a pinnacle. An approach angle of approximately 13°  to 15° is considered a steep approach.  [Figure 10-4]  Caution  must be exercised to avoid the parameters for vortex ring  state (20–100 percent of available power applied, airspeed  of less than 10 knots, and a rate of descent greater than 300  feet per minute (fpm)). For additional information on vortex  ring state (formerly referenced as settling-with-power), refer  to Chapter 11, Helicopter Emergencies and Hazards. 1.  Initiating the maneuver by lowering the collective  without aft cyclic pressure to maintain altitude.  2.  Initially applying aft cyclic stick too rapidly, causing  the helicopter to balloon (climb).  3.  Failing to effectively control the rate of deceleration  to accomplish the desired results.  4.  Allowing the helicopter to stop forward motion in a  tail-low attitude.  5.  Failing to maintain proper rotor rpm.  6.  Waiting too long to apply collective pitch (power)  during the recovery, resulting in an overtorque  situation when collective pitch is applied rapidly.  7.  Failing to maintain a safe clearance over the terrain.  8.  Using antitorque pedals improperly, resulting in erratic  heading changes. 9.  Using an excessively nose-high attitude. 10-5