Aircraft Skydrol Hydraulic Fluid

Buy aviation skydrol fluid for use in aircraft, HPUs, and fluid service units. Skydrol fluid includes 500B4, LD-4, and Skydrol 5.


Skydrol LD-4 was introduced in 1977 , and is well known around the world. At the time of its introduction it was a breakthrough product, solving problems of valve erosion and thermal stability common in earlier fluids. Its excellent thermal stability under real world conditions has given it a reputation as the gold standard among Type IV fluids. Skydrol LD-4 features low density, excellent thermal stability, valve erosion prevention, and deposit control.

ManufacturerPart NumberDescription
Eastman LD4-1GALEastmanLD4-1GAL1 Gallon
Eastman LD4-55GALEastmanLD4-55GAL55 Gallon Drum
Eastman LD4-5GALEastmanLD4-5GAL5 Gallon Drum

The Skydrol 500 series of fluids has the longest service history among phosphate ester products. The first version, Skydrol 500, was introduced in 1952. Steady improvements to the formulation led in 1977 to the current version, Skydrol 500B-4 which contains the same breakthrough anti-erosion additive and acid scavenger found in Skydrol LD-4 . Skydrol 500B-4 is the most worker friendly of the aviation phosphate esters; it is least irritating to skin and less prone to form mists which can be irritating to the respiratory tract . This has given the product enormous popularity for use in workshops and indoor test stands.

ManufacturerPart NumberDescription
Eastman 500B4-1GALEastman500B4-1GAL1 Gallon
Eastman 500B4-55GALEastman500B4-55GAL55 Gallon Drum
Eastman 500B4-5GALEastman500B4-5GAL5 Gallon Drum
Skydrol 5
Introduced in 1996, Skydrol 5 was the first Type V fluid qualified under the Boeing BMS 3-11 specification. Skydrol 5 offers higher temperature capability than Type IV fluids, the lowest density, and better paint compatibility. Skydrol 5 does not have universal airframe manufacturer approval, so please consult Eastman's Skydrol Technical Service (800-260-4150) for specific approval and application information.
ManufacturerPart NumberDescription
Eastman Sky5-1GALEastmanSky5-1GAL1 Gallon
Eastman Sky5-55GALEastmanSky5-55GAL55 Gallon Drum
Eastman Sky5-5GALEastmanSky5-5GAL5 Gallon Drum