Abstract: A rotor system for a rotor convertible fixed winged aircraft comprising a rotatable rotor shaft mounted on one of the wings of the aircraft, the shaft tiltable between a substantially vertical position and a substantially horizontal position, a rotor mounted to the shaft and including at least one blade, the blade having an adjustable blade angle relative to the shaft, apparatus for tilting the shaft between the vertical and horizontal positions, controls responsive to the tilting of the shaft for automatically adjusting the blade angle of a blade to an autogyro blade angle when the shaft is in the vertical position and to a substantially feathered blade angle when the shaft is in the horizontal position.