Eastman - SKYDROL-LD-4 (1-Usqt-Can)

• Low Density: Skydrol LD-4 boasts a low density, making it lightweight and efficient, ideal for aircraft systems where weight is a critical factor.
• Excellent Thermal Stability: Even under real-world conditions, Skydrol LD-4 maintains outstanding thermal stability, ensuring reliable performance in various temperatures.
• Valve Erosion Prevention: This fluid is formulated to prevent valve erosion, enhancing the longevity and efficiency of aircraft systems, reducing maintenance requirements.
• Deposit Control: Skydrol LD-4 effectively controls deposits, minimizing the risk of clogs or malfunctions in crucial aircraft components, thus ensuring optimal performance.

IDENTIFICATION

Product name: Skydrol LD4 Fire Resistant Hydraulic Fluid
Product code: 34102-00, P3410207, P3410200, P3410206, P3410204, P3410202, P3410205, P3410203, E3410201, P3410208, P3410209

Spec Codes

Boeing Spec Numbers: BMS 3-11P, Type V, Grade B & C 

Other Spec / Approval Codes & Manufacturer References for the LD-4 Hydraulic Fluid product may include:

• NSA 307110 (Identified on several vendor spec listings as an “Airbus PN/Spec” or “NSA/NS - ” code).
  
• BAMS 564-003, (This appears in cross references including Bombardier spec).
  
• SAE AS1241   (Seen in Skydrol LD4 Hydraulic Fluid vendor listings).
  
• DMS 2014H R-1 (Also seen in Skydrol LD4 Hydraulic Fluid vendor spec listing).

Generic Alternative Possible Names:

SKYDROL LD4, SKYDROLLD4, SKYDR0LLD4-1QT, SKYDROL-LD4-1GL, SKYDROL LD4 / 1QT/CAN, SKYDROL LD-4, LD4, SKYDROL-LD4-1QT, SKYDR0LLD4:PW582, LD4-QT, LD-4, LD-4, Leak Detect Powder, SKYDR0LLD4QT, SKYDROL-LD4, SKYDROL_LD4,  BMS3-11N-TY4-CL1-GRA, BMS3-11N-TY4-CL1

Aerospheres Skydrol LD4 Product Review:

Key Features of Skydrol LD4

Fire Resistance and Safety
Skydrol LD-4 does very well in reducing fire risk. The high flash points, fire point, and autoignition temp make it much safer under system failures, leaks, or ruptures near hot surfaces. That’s a critical advantage in aircraft hydraulics.

Thermal Stability
It’s been shown to resist thermal breakdown, avoiding sludge, varnish, and deposit formation that can plague lesser fluids. For systems that undergo large temperature swings (from very cold at altitude to very hot in use or in hot climes), Skydrol LD-4 holds up.

Low Temperature Behavior
The pour point of ~ -62°C (~ -80°F) and the limiting viscosity at low temp allow hydraulic systems to function (though slowly) at very cold temperatures, which is essential for high-altitude flight.

Weight Savings
Low density means reduced mass in fluid carried, which is nontrivial in aviation. Over many liters, that results in modest fuel savings or improved performance.

Well-Established Track Record
It’s been around since the late 1970s, with decades of operational experience. The specifications are well understood, maintenance practices established, and there is widespread OEM acceptance. Reliability is thus less of an unknown.

Overall Impression

Skydrol LD4 is a top-tier hydraulic fluid for aviation applications. If you are designing or maintaining flight control, landing gear, brakes, flaps etc., LD4 delivers a strong combination of fire safety, thermal stability, and operational performance, especially under demanding conditions.

For operations that regularly face extreme cold or where system weight is highly constrained, it may be worth considering whether more modern fluids (or Type V fluids, or fluids with lower cold-viscosity, etc.) offer advantages, but Skydrol LD4 remains a strong benchmark.

So overall, I’d probably give it an 8.5/10 for aviation hydraulic fluid, assuming the user has good maintenance practices and handles the limitations well.