MIL-H-5606 is which type of fluid?

MIL-H-5606 is which type of fluid?

• A. Petroleum based
• B. Water based
• C. Silicone based
• D. Synthetic ester

Answer: (A)

This question tests knowledge of what MIL-H-5606 specifies for aircraft hydraulic fluid. MIL-H-5606 is a petroleum-based hydraulic fluid, meaning it’s mineral-oil–based with additives to protect against oxidation, corrosion, wear, and to ensure compatibility with seals and materials. It’s also commonly recognized by its red color in many systems. That’s why the correct choice is petroleum-based. Water-based fluids are a different category and are not MIL-H-5606, as water content can cause corrosion and microbial growth in aircraft systems. Silicone-based fluids and synthetic ester fluids belong to other fluid families with different performance characteristics and specifications, so they aren’t MIL-H-5606.

This question tests knowledge of what MIL-H-5606 specifies for aircraft hydraulic fluid. MIL-H-5606 is a petroleum-based hydraulic fluid, meaning it’s mineral-oil–based with additives to protect against oxidation, corrosion, wear, and to ensure compatibility with seals and materials. It’s also commonly recognized by its red color in many systems.

That’s why the correct choice is petroleum-based. Water-based fluids are a different category and are not MIL-H-5606, as water content can cause corrosion and microbial growth in aircraft systems. Silicone-based fluids and synthetic ester fluids belong to other fluid families with different performance characteristics and specifications, so they aren’t MIL-H-5606.