The aircraft hydraulic system is an integral part of any aircraft for the movement and actuation of various hydraulic systems. For a typical aircraft, these often include systems and equipment such as aircraft wheel brakes, bay doors, handle wing flaps, and many other flight pertinent components. Even the autopilot system contains servos that are operated by hydraulic actuators, allowing manipulation of control services. Hydraulic systems work through the enacting of pressure upon enclosed fluids, then transferring that pressure throughout the system to actuate a command. Hydraulic systems are extremely reliable, efficient, and easy to maintain, making them very suitable for aircraft control. In this article, we will discuss the advantages of the hydraulic system, as well as some challenges faced in hydraulic design.