U.S. Patent Specifications

In a rotating wing aircraft, a rotating wing with variable incidence blades, hand operated means for positively setting the incidence angle of said blades to cither of two predetermined positions corresponding to helicopter and autogiro conditions of the rotating wing, respectively, first means for locking and unlocking said setting means in their autogiro position, second means for locking and unlocking said setting means in their helicopter position and means for positively readjusting the position of said second means within a small range about said pre‐determined helicopter position, whereby the torque consumption of the rotating wing can be suited to the engine output in the helicopter condition, under variable helicopter flying conditions.