Regarding Skydrol hydraulic fluid, which statement is true?

Skydrol hydraulic fluid is a phosphate ester-based fluid commonly used in aviation for its fire-resistant properties and performance in hydraulic systems. The statement regarding its resistance to most common aircraft metals and epoxy paints is accurate because Skydrol exhibits compatibility with a variety of materials used in aircraft construction. This resistance is a crucial feature, as it ensures that the hydraulic fluid does not corrode or degrade the metals and coatings it comes into contact with during operation.

Understanding the compatibility of Skydrol with aircraft materials is vital for maintaining the integrity of hydraulic systems, as adverse reactions could lead to system failures or safety hazards. This makes Skydrol a preferred choice in aviation where hydraulic systems are exposed to a variety of materials and environmental conditions. The other statements present inaccuracies regarding the fluid's compatibility and use; for example, Skydrol is not suitable for nylon, it is not limited to composite structures, and it does possess some compatibility issues, particularly with certain plastics and elastomers.