The Functionality of an Aircraft Hydraulic System

Hydraulic systems are a staple of modern aircraft, such technology taking advantage of the properties of compressed fluids situated in enclosed spaces to create harnessable force. With hydraulic systems, aircraft are able to effectively control flight surfaces, deploy and retract landing gear, and much more. In this blog, we will provide a brief and basic overview of the aircraft hydraulic system, allowing you to have a better understanding of its design, use, and capabilities.

Every hydraulic system follows Pascal’s Law, a working principle that describes how hydraulic fluids exert equal pressure at every point and in every direction of the fluid. With this, an aviation hydraulic system is able to adjust components between positions through the use of pressurized fluids. Generally, aircraft use these systems for the means of operating flight control surfaces, lending gear, thrust reversers, and brakes.

While hydraulic systems may vary based on the complexity of the aircraft and its needs, most will consist of the same basic parts. These include a source of hydraulic power, pipes or hoses for hydraulic fluid transportation, a valve mechanism for flow and directional control, a device for fluid power conversion, and a reservoir for hydraulic fluid storage.

Hydraulic fluids are known for being extremely optimal in their functionality, often operating with nearly 100 percent efficiency. Typically, the only loss that is faced by the system will come in the form of fluid friction which is hard to completely deter. Nevertheless, there are many benefits to hydraulic systems, including the fact that they are lightweight, cost effective, easy to install, simple to inspect, and have minimum maintenance requirements to keep everything running smoothly.

Based on the systems and assemblies on an aircraft, a single vehicle may have numerous hydraulic systems. For example, the Airbus A320 has three independent hydraulic systems, those of which are known as the green, yellow, and blue hydraulic systems. Each of these systems will contain a normal and auxiliary power source, and their list of components will slightly vary to accommodate the particular systems that they support.

To protect a hydraulic system, one must implement proper filtration which is upheld through the use of filters. Hydraulic filters are designed to capture and filter out any particles that are present in hydraulic fluids, those of which may cause wear and tear to assemblies or deter overall performance. Generally, the most common filters are HP, LP, and case drain filters, each of which are designed for a different section of the hydraulic system. To ensure cleanliness is upheld, filters should be replaced on a regular basis, many products offering a red clogging indicator that will pop out when it is time for replacement.

If you are in the market for top-quality aircraft hydraulic system parts to support the operations of control surfaces, landing gear, thrust reversers, or other such assemblies, look no further than Purchasing Synergy. Owned and operated by ASAP Semiconductor, we present customers access to over 2 billion new, used, obsolete, and hard-to-find parts that have been sourced from leading manufacturers that we trust. Every listing on our database is ready for purchase at any time, and we encourage you to take advantage of our online RFQ services to quickly request quotes on items of interest. Utilizing the information that you offer us on your form, our team will craft a customized solution for you and present it in 15 minutes or less. We can also be called or emailed at any time, and our team would be more than happy to assist you however possible. Get in contact with a team member today and experience how we can operate as your strategic sourcing partner for all your operational requirements. 


February 15, 2023
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