What we mean by aviation hydraulic fluids and preservatives

What are aircraft hydraulic fluids? They’re fluids usually made up of mineral oils or synthetic hydrocarbons, which are to be used in hydraulic applications within an aircraft. Depending on the aviation hydraulic fluid, they might be used for brakes, shock absorbers, gearboxes or other applications.

What are aircraft preservatives? They’re lubricants that are used to protect aircraft, including engines and components. Aircraft preservatives can be used for purposes like protecting your aircraft against corrosion or lubricating it during storage. Read through our technical talk page on preservation oils to learn more about these lubricants.

Mineral hydraulic fluids

  • AeroShell Fluid 41

    AeroShell Fluid 41

    • Super clean mineral hydraulic fluid.
    • Approved to MIL-PRF-5606.

    AeroShell Fluid 41 is a mineral hydraulic oil manufactured to a very high level of cleanliness and it possesses improved fluid properties.

    It contains additives that provide excellent low-temperature fluidity as well as exceptional anti-wear, oxidation – corrosion inhibition and shear stability. In addition, metal de-activators and foam inhibitors are included in this high-viscosity index fluid to enhance performance in hydraulic applications.

    AeroShell Fluid 41 is dyed red.


    Find the AeroShell Fluid 41 data sheet

  • AeroShell Landing Gear Fluid

    AeroShell Landing Gear Fluid

    • Extreme pressure operational hydraulic fluid;
    • Based on AeroShell Fluid 41 which already provides strong oxidation stability and anti-wear performance; and
    • Approved to BMS 3-32 Type 2.

    AeroShell Landing Gear Fluid (LGF) is a mineral hydraulic fluid (MIL-PRF-5606) to which additional additives have been added to improve the extreme pressure characteristics and the fluid’s natural lubricity. The lubricity agent provides a stable thin film layer to the metal surfaces at mild operating conditions. When severe conditions exist (landing/touchdown), the extreme pressure additive supplies the load carrying needed at the metal-to-metal surfaces to prevent the occurrence of such phenomena as ‘ladder cracking’ and ‘slip stiction’ of the piston component of the landing gear.

    AeroShell LGF is dyed yellow.

    Find the AeroShell LGF data sheet

  • AeroShell Fluid 4

    AeroShell Fluid 4

    • Only available in the Americas region.

    AeroShell Fluid 4 is a mineral hydraulic oil with very good low temperature characteristics and capable of operating over a wide temperature range. AeroShell Fluid 4 is composed of a mineral oil base stock and a complex additive package, which results in a product with excellent low-temperature flow and anti-wear properties, exceptional anti-foam characteristics and excellent oxidation stability.

    AeroShell Fluid 4 is dyed red.

    Find the AeroShell Fluid 4 data sheet

Synthetic hydrocarbon hydraulic fluids

  • AeroShell Fluid 31

    AeroShell Fluid 31

    • Super-clean, fire-resistant, synthetic hydrocarbon hydraulic fluid.
    • Approved to MIL-PRF-83282.

    AeroShell Fluid 31 is a synthetic hydrocarbon-based aircraft hydraulic fluid with greatly improved fire resistance characteristics. AeroShell Fluid 31 has a specially designed base stock that imparts a relatively high flash point, excellent low-temperature properties and good oxidation and thermal stability. In addition, AeroShell Fluid 31 is formulated with high-technology additives to provide oxidation and corrosion resistance, anti-wear and anti-foaming protection. AeroShell Fluid 31 is superclean filtered to ensure optimum performance in particulate monitored systems.

    AeroShell Fluid 31 is dyed red.

    Find the AeroShell Fluid 31 data sheet

  • AeroShell Fluid 61

    AeroShell Fluid 61

    • Preservative, synthetic hydrocarbon hydraulic fluid.
    • Approved to MIL-PRF-46170 Type 1.

    AeroShell Fluid 61 is a synthetic hydrocarbon base hydraulic fluid specifically inhibited to provide excellent oxidation stability for the oil and good corrosion preventive protection to the hydraulic system.


    Find the AeroShell Fluid 61 data sheet

The AeroShell preservation oil range

Other AeroShell fluids