The Functionality of Aircraft Hydraulic Systems
Hydraulic systems are a fundamental component in the design and construction of modern aircraft. As the engineering of hydraulic systems evolved over time, and the technology became more elaborate, aircraft designers began implementing hydraulic systems for many more aircraft functions. This is due, in part, to the fact that hydraulic systems are economically friendly to install, easy to maintain, and can still perform in the most demanding in-flight conditions. Modern aircraft use hydraulic systems to support for the operation of several flight-critical functions.
The most common application of aircraft hydraulic systems are flight control surfaces, landing gear, and brakes. The fundamentals of aircraft hydraulics are virtually the same regardless of different aircraft styles. Whether it be a small single-engine propeller-powered plane or a multi-engine jet transport, the design of the hydraulic maintains a structural integrity. Hydraulics are designed to be lightweight, easy to install, and simple to maintain. Hydraulics function efficiently with very little friction-related loss of fluid.
Depending on the purpose that the hydraulic system is intended to achieve, it is not uncommon to need to install redundant systems to facilitate safe operation of the aircraft. This can aid in the event that a hydraulic system fails. Many aircraft hydraulic systems share the same basic foundation. This includes a pump, reservoir, actuating cylinder, pressure relief valve, and heat exchanger. Regardless of the scope and scale of the system itself, these main elements will always be present.
The process in which aircraft hydraulic system operates is simple. A pressurized liquid is used to move a specific part of the vessel from one position to another. Depending on the weight of an aircraft, the operating pressure can vary from a few hundred pounds per square inch to a whopping five thousand pounds per square inch. When the pump is activated, it pressurizes the system, which puts the actuator in motion. The directional movement of the actuator is transferred to another surface, such as landing gear, brakes, even a cargo ramp. Pressure is then released from the system to reverse the movement.
Aircraft hydraulic systems have efficient responses to control inputs. This allows the pilot to execute flight control functions with ease, without worry, and most importantly, safely.