Abstract: An autogyro aircraft has freewheeling rotor blades that provide lift. A separate pusher propeller provides forward thrust. The rotor system (20) has a collective arm (30) as a control for selectively setting and maintaining a tension force on a collective cable to regulate the rotor blade angle of attack or pitch angle between a no-lift attitude and a positive lift angle. The collective arm (30) sets a tension on collective cable against a coil spring biasing. The collective arm is connected to pivot or tilt a pitch change horn assembly and, in turn, connected rotor blades. The collective arm can be selectively set and maintained and released and reset both on the ground and in flight.