rigid rotor

A rotor head that allows the blades freedom to feather but not to flap or lead-lag. The rotor head has to absorb all the forces generated during flight maneuvers. Control loads in this type of rotor head are high; however, this type imparts the most control power to the helicopter during flight. Rigid rotor heads are expensive to manufacture and maintain because of the materials involved in their construction, but they are the only type of rotor system to give the aircraft some aerobatic capabilities.

In rigid rotor hubs, a gimbal-mounted control consisting of spoke-like fly weights is mounted on the same mast with the rotor. When the pilot deflects the stick, the force applied at A through the swash plate is felt at B, i.e., 90° in the direction of the rotation. This force displaces the rotor from parallel planes, individually changing the blade pitch through shafts from the control rotor blades to respective pitch horns on the main rotor blades. This tilts the rotor disc in the direction of pitch or roll indicated by the original control force.