text: during autorotation descent would be obtained 
  at the flight condition which produces the 
  greatest proportion between airspeed and rate 
  of descent. Thus, a straight 
  line from the 
  tangent to the curve will define the 
  origin 
  point 
  for maximum autorotative glide dis- 
  tance. This corresponds to Point B of figure 
  6.18. 
  If the helicopter is being glided at the 
  speed for maximum glide distance, a decrease 
  in airspeed would reduce the rate of descent 
  but the glide distance would decrease. If the 
  helicopter is being glided at the speed for 
  minimum rate of descent, the rate of descent 
  (steady state) can not be reduced but the glide 
  distance can be increased by increasing the 
  for maximum distance. 
  glide speed to 
  Weight and wind affect the glide character- 
  istics of a helicopter the same way an airplane 
  is affected. 
  Ideally, the helicopter autorotates 
  at a higher equivalent airspeed at higher gross 
  weight or when autorotating into a headwind. 
  In addition to aerodynamic forces which act 
  on the rotor during autorotation, inertia forces 
  are also important. These effects are usually 
  associated with 
  response time be- 
  the pilot’s 
  cause the rate a pilot reacts to a power failure 
  is quite critical. The time necessary to reduce 
  collective pitch and enter autorotation be- 
  comes critical if the rotor inertia characteristics 
  are such as to allow the rotor to slow down to 
  a dangerous level before the pilot can react. 
  With power on, the blade pitch is relatively 
  high and the engine supplies enough torque to 
  the 
  overcome the drag of the blades. At 
  instant of power failure the blades are at a high 
  pitch with high drag. 
  If there is no engine 
  torque to maintain the RPM, the rotor will 
  decelerate depending on the rotor torque and 
  If the rotor has high rotational 
  rotor inertia. 
  energy the rotor will 
  lose RPM less rapidly, 
  giving the pilot more time to reduce collective 
  pitch and enter autorotation. 
  If the rotor has 
  low rotational energy, the rotor will lose RPM 
  rapidly and the pilot may not be able to react 
  quickly enough to prevent a serious loss of 
  rotor RPM. Once the collective pitch is at 