text: by the actuator and none of the hinge moments 
  are fed back through 
  In such 
  a control system, the control position decides 
  the deflection of the control surfaces regardless 
  of the airloads and hinge moments. Since the 
  power-operated control system has zero feed- 
  back, control feel must be synthesized other- 
  wise an infinite boost would exist. 
  
  the controls. 
  
  The advantages of the power-operated COR- 
  
  trol system are most apparent in transonic and 
  In transonic flight, none of 
  supersonic flight. 
  the erratic hinge moments are fed back to the 
  pilot. 
  Thus, no unusual or erratic control 
  forces,will be encountered in transonic flight. 
  Supersonic flight generally requires the use of 
  an all-movable horizontal surface to achieve 
  the necessary control effectiveness. Such con- 
  trol surfaces must then be actuated and posi- 
  tively positioned by an irreversible device. 