Collective pitch change system for teter-bar type gyroplane rotary wing aircraft

Collective pitch change means for a rotor assembly of a gyroplane rotary wing aircraft wherein the rotor assembly is mounted on a rotatable hub and includes a pair of blades attached to opposite ends of a central teter-bar having a pivotal mounting which permits the teter-bar and attached blades to move together in a see-saw type motion, said collective pitch change means comprising:

• adjustable blade attachment means at each opposed end of the teter-bar for attaching the blades to the teter-bar, each said adjustable blade attachment means including a feathering pivot for permitting rotation of the blades around a feathering axis which extends generally radially from said hub lengthwise along said teter-bar to change the pitch of the blade, pitch adjustment means for rotating the blade relative to the teter-bar around said feathering pivot, said pitch adjustment means including a first actuator mounted on said said teter-bar for limited movement in a direction generally parallel to said feathering axis, spring bias means mounted on said teter-bar for supplying motive force to move said first actuator relative to said teter-bar, and means coupled to said first actuator for exerting a relative force between the teter-bar and the blade to change the pitch of the blade when said first actuator is moved by said spring bias means, simultaneous actuator means for operating both said pitch adjustment means together such that the pitch is changed simultaneously on both blades, and release means for retaining said spring bias means in an energy storage mode in which said spring bias means is restrained from supplying motive force to said first actuators and for selectively releasing said spring bias means from said energy storage mode whereby spring energy moves said first actuators to change the pitch of said blades.