Aircraft actuator hydraulic system

An aircraft actuator hydraulic system that includes hydraulically operated actuators for driving a control surface of an aircraft having a body and wings and that supplies pressure oil to the actuators, the system comprising:

• a first actuator provided as one of the actuators and configured to drive the control surface by being operated by supply of pressure oil from a first aircraft central hydraulic power source including a first aircraft central hydraulic pump;
• a second actuator provided as another one of the actuators and configured to drive the control surface by being operated by supply of pressure oil from a second aircraft central hydraulic power source including a second aircraft central hydraulic pump;
• wherein the first aircraft central hydraulic pump and the second aircraft central hydraulic pump are disposed in the body of the aircraft;
• and
• a backup hydraulic pump installed inside a wing of the aircraft and to supply pressure oil to the first actuator when a loss or degradation in a function of at least one of the first aircraft central hydraulic power source and the second aircraft central hydraulic power source occurs,
• wherein a maximum discharge pressure of the backup hydraulic pump is unadjustably set to be greater than maximum discharge pressures of the first aircraft central hydraulic pump and the second aircraft central hydraulic pump.