Abstract: A hydraulic fluid powered actuation system preferably for controlling the position of a control surface of an aircraft in response to a plurality of redundant control signals is disclosed. The system comprises an actuator adapted to be mounted in the aircraft, comprising a housing having first and second cylinders with a piston moveably mounted within each of the cylinders. A piston rod connects the pistons and is adapted to engage the control surface. Two rotary torque motors having a common drive shaft are provided which are adapted to receive the plurality of redundant controls signals. First and second rotary control valves, coupled to the drive shaft, and thus, adapted to be driven by the rotary torque motors, are used to control the emission and exhaust of hydraulic fluid from the first and second cylinders, respectively. Preferably, there are four control signals and the torque motors are DC, multiple-poled torque motors with each coil on each torque motor coupled to a different control signal.