What is the nominal hydraulic pressure for both the primary and secondary circuits?

What is the nominal hydraulic pressure for both the primary and secondary circuits?

• A. 870 psi
• B. 860 psi
• C. 900 psi
• D. 800 psi

Answer: (A)

The hydraulic system is designed around a single, standard operating pressure for reliable and predictable control, and that value is 870 psi for both the primary and the secondary circuits. Using the same nominal pressure in both circuits gives the pilot a consistent control feel and ensures that the various flight-control actuators and systems respond in a uniform way. In normal operation you’ll see around this pressure, but actual readings can shift with pump performance, temperature, and load demands while staying within the system’s designed tolerance. Values significantly higher or lower than 870 psi would change actuator loads and control feel, so 870 psi is chosen as the design standard.

The hydraulic system is designed around a single, standard operating pressure for reliable and predictable control, and that value is 870 psi for both the primary and the secondary circuits. Using the same nominal pressure in both circuits gives the pilot a consistent control feel and ensures that the various flight-control actuators and systems respond in a uniform way. In normal operation you’ll see around this pressure, but actual readings can shift with pump performance, temperature, and load demands while staying within the system’s designed tolerance. Values significantly higher or lower than 870 psi would change actuator loads and control feel, so 870 psi is chosen as the design standard.