Skydrol Systems

Skydrol Aviation Hydraulic Fluid

Skydrol is the most advanced aviation hydraulic fluid supported by recognized experts in phosphate-ester fluid technology. The Skydrol line of fire resistant hydraulic fluids includes Skydrol 500B-4, Skydrol LD-4, Skydrol 5 and Skydrol PE-5. Skydrol PE-5 was developed to meet the new "harmonized" hydraulic fluid specifications, which are a single set of Type V hydraulic fluid requirements developed by Airbus, Boeing, and the hydraulic fluid manufacturers.

History of Fluid Development

In 1948, Douglas Aircraft Company and Monsanto cooperatively developed Skydrol 7000, the first phosphate ester fire resistant hydraulic fluid to address the growing number of aircraft hydraulic fluid fires. With advancements in aircraft designs, improved hydraulic fluid performance was needed. Airframe manufactures' specifications defined these performance enhancements via Type I, II, III and IV designations.

Since 1977, Skydrol LD-4 and 500B-4 have met the performance demands of commercial aircraft.

Skydrol 5, introduced in 1996, was the first Type V fluid approved under BMS3-11. It still offers the lowest density of any phosphate ester fluid, plus better paint compatibility and thermal stability compared to Type IV fluids.

Skydrol PE-5, the newest Type V fluid, is approved by both Boeing and Airbus, and compatible with all aircraft using phosphate ester fluids. It offers the longest fluid life of any phosphate ester fluid, plus improvements over Type IV fluids in density and low temperature viscosity.

RSG and Skydrol

Royal Systems Group designs ground support systems for the aviation industry. Our test stands give the customer the capability to test the hydraulic components from a custom touch screen built to their specifications.

Skydrol Chronology