Blade Pitch Angle

Rotorcraft Flying Menu >General Aerodynamics >Airfoil > Blade Pitch Angle

The pitch angle of a rotor blade is the angle between its chord line and the reference plane containing the rotor hub. [Figure 2-4] You control the pitch angle of the blades with the flight controls. The collective pitch changes each rotor blade an equal amount of pitch no matter where it is located in the plane of rotation (rotor disc) and is used to change rotor thrust. The cyclic pitch control changes the pitch of each blade as a function of where it is in the plane of rotation. This allows for trimming the helicopter in pitch and roll during forward flight and for maneuvering in all flight conditions.

Figure 2-4. Do not confuse the axis of rotation with the rotor mast. The only time they coincide is when the tip-path plane is perpendicular to the rotor mast.