What powers the operability valve?

What powers the operability valve?

• A. Fuel pressure directed by the FADEC
• B. Electrical power from the battery
• C. Hydraulic pressure
• D. Ambient air pressure

Answer: (A)

Operability valves are actuated by the pressure of the fuel itself. The FADEC controls the valve by directing high-pressure fuel to it, using that fuel pressure as the force to move the valve to the commanded position. Electrical power from the battery may run the FADEC’s electronics, but it does not directly drive the valve. Ambient air pressure can’t provide the necessary actuation, and a separate hydraulic system isn’t used for this valve—the fuel pressure controlled by the FADEC is the actuation source.

Operability valves are actuated by the pressure of the fuel itself. The FADEC controls the valve by directing high-pressure fuel to it, using that fuel pressure as the force to move the valve to the commanded position. Electrical power from the battery may run the FADEC’s electronics, but it does not directly drive the valve. Ambient air pressure can’t provide the necessary actuation, and a separate hydraulic system isn’t used for this valve—the fuel pressure controlled by the FADEC is the actuation source.