What is the primary use of hydraulic fluids in aircraft?

Hydraulic fluids play a crucial role in aircraft systems by transmitting power. In most aircraft, hydraulic systems are used to operate various components such as landing gear, flaps, brakes, and flight control surfaces. The hydraulic fluid transfers force from one location to another, allowing for the effective and efficient operation of these systems.

The hydraulic system works on the principle of Pascal's law, which states that pressure applied to a confined fluid is transmitted undiminished in all directions. This allows for significant mechanical advantages and makes it possible to control heavy components with relative ease. The specific characteristics of hydraulic fluids—such as their ability to lubricate, resist temperature changes, and provide protection against corrosion—enhance their effectiveness in this application.

While hydraulic fluids do have some other applications, such as assisting with the operation of various cleaning systems or influencing cabin pressure indirectly, their primary function in an aircraft is to facilitate the transmission of power within hydraulic systems.