When option attachment has not been attached, a reserve flow/direction control valve 8 is made to operate as a center bypass cut valve. When an option attachment has been attached, switching control is performed. In the switching control, when the option attachment is not used, the reserve flow/direction control valve 8 is made to operate as a center bypass cut valve for adjusting composite opening area of a center bypass and thereby controlling the flow rate of hydraulic fluid flowing into an actuator. When the option attachment is used, the reserve flow/direction control valve 8 is made to operate so as to supply the hydraulic fluid to an option hydraulic actuator 14.

Aspects relate to systems and methods for controlling landing gear of an aircraft. An exemplary system includes a nose gear located at a nose of the aircraft, where the nose gear includes a nose piston configured to allow for displacement of a nose wheel relative the aircraft, a main gear located aft of the nose gear, where the main gear includes a main piston configured to allow for displacement of a main wheel relative the aircraft, a hydraulic circuit in fluidic communication with each of the nose piston and the main piston, and a compliant element in fluidic communication with the hydraulic circuit and configured to provide a compliant response at one or both of the nose piston and the main piston.