14.76 Helicopter Controls

14.76.2 With respect to helicopter controls, explain the purpose and the basic principle of operation of the following:

(a) collective control;

Purpose:

• Controls the overall lift (thrust) produced by the main rotor
• Used to climb, descend, or maintain height

Operation:

• Moving the collective lever changes the pitch angle of all rotor blades equally and simultaneously
• Increasing collective:
  • Increases blade angle of attack
  • Increases lift and induced drag
  • Requires more power
• Decreasing collective:
  • Decreases blade angle of attack
  • Reduces lift
   

Summary:
The collective changes all blade pitch together, controlling lift and vertical movement of the helicopter.

(b) cyclic control;

Purpose:

• Controls the direction of flight (pitch and roll)
• Tilts the rotor disc to move the helicopter