Abstract: Individual blade control of a helicopter rotor is accomplished by rotation of a mast (10) about a standpipe (12) where an individual blade (16) is coupled to the mast through a hub (18). Pilot input signals are transmitted by fly-by-optic transmission lines (14) through a fiber optic slip ring (40,42) to signal generators (134, 136, 138) for each of three sections of triplex actuators (76-79) coupled to individual rotor blades. Hydraulic fluid for positioning each of the actuators (76-79) is provided by electrohydraulic power packages (88, 90 and 92) where each package includes a pump and alternator. As each blade rotates about the mast (76) the pitch angle changes by individualizing the output of the signal generators (134-138) for each actuator.

Abstract: A helicopter mast is driven by a transmission with a swashplate individually linked to pitch horns on each rotor blade. At least four actuators are coupled to the swashplate, three of which normally control the attitude and position of the swashplate. A separate power unit is provided for each actuator, each power unit being independently driven from the transmission. Means are then provided to shift control of the swashplate from one of the three actuators to a fourth actuator upon any one becoming disabled.