Abstract: Apparatus for providing actuation power to an aircraft flight control surface. The apparatus includes a first actuator and a second actuator, where the second actuator has a bypass mode and an assist mode. The mode of the second actuator is determined by an internal differential pressure across the first actuator. The apparatus further includes a mode select valve for selecting between the bypass mode and the assist mode for the second actuator, and a solenoid valve that when energized causes the mode select valve to select the other mode for the second actuator. When the second actuator is in the bypass mode, the first actuator provides the actuation power for the aircraft flight control surface. But, when the second actuator is in the assist mode, both the first and second actuators provide the actuation power for the aircraft flight control surface. Accordingly, the apparatus allows the flight control surface to be operated in a more efficient manner with less hydraulic flow being required.