text: The only immediate solution for the dynamic 
  is an attitude stabilization system 
  instability 
  which 
  is essentially an autopilot. Other 
  solutions to the dynamic instability problem 
  involve mechanical, aerodynamic, or elec- 
  tronic control 
  feedback of pitch attitude, 
  pitch velocity, normal acceleration, or angle 
  the heli- 
  of attack. 
  copter’s stability is mandatory to fully utilize 
  its unique capability. As more of the heli- 
  copter problems are analyzed and studied, the 
  flying qualities of helicopters wiI1 improve 
  and be comparable to the fixed wing aircraft. 
  
  The improvement of 