Which valve allows fuel to leave the airplane so the gross weight can be reduced for emergency landing?

• A. Jettison Valve
• B. Cross-Feed Valve
• C. Firewall Shutoff
• D. Refuel or Fill Valve

Answer: (A)

The key idea is a fuel jettison system used to quickly reduce aircraft weight to meet safe landing limits. The valve that enables fuel to leave the airplane is the jettison valve. When opened, fuel is dumped from designated tanks through a dedicated line and nozzle into the airstream, typically away from the fuselage and ignition sources, allowing a controlled decrease in gross weight for an emergency landing.

Understanding the other valves helps see why this is the right one:

• The cross-feed valve moves fuel between tanks, often to balance weight or ensure an engine continues to receive fuel. It doesn’t vent fuel from the airplane.

• The firewall shutoff valve is a safety feature that stops fuel flow to the engines in case of fire or other emergencies.

• The refuel or fill valve is used during fueling operations to load fuel into the tanks, not to dispose of it.

So, dumping fuel to reduce weight in an emergency is accomplished by the jettison valve.