What triggers the transfer valves to open?

What triggers the transfer valves to open?

• A. They automatically open when the tank low level sensors are dry.
• B. They open when the aircraft reaches a certain altitude.
• C. They require manual operation from the crew.
• D. They open only after the center tank is full.

Answer: (A)

The system uses direct tank level sensing to manage fuel flow. Transfer valves open automatically whenever a tank’s low-level sensor indicates the tank is dry (no fuel). This lets fuel be moved from the other tank (typically from the center tank) into the empty tank so engine feed isn’t interrupted and the aircraft remains balanced. Once fuel is detected in the previously dry tank again, the valves close. There’s no need for crew action, and the trigger is not related to altitude or to the center tank being full.

The system uses direct tank level sensing to manage fuel flow. Transfer valves open automatically whenever a tank’s low-level sensor indicates the tank is dry (no fuel). This lets fuel be moved from the other tank (typically from the center tank) into the empty tank so engine feed isn’t interrupted and the aircraft remains balanced. Once fuel is detected in the previously dry tank again, the valves close. There’s no need for crew action, and the trigger is not related to altitude or to the center tank being full.