General Authority of Civil Aviation (GACA) Aeronautical Information Publication (AIP) Practice Exam

Can fuel be jettisoned from the center tank if the pumps are turned OFF?

1. Yes, it can still be jettisoned

2. No, it will not jettison without pumps ON

3. Yes, but at a reduced rate

4. No, due to pressure issues

The correct answer is: No, it will not jettison without pumps ON

Fuel jettisoning from the center tank relies primarily on the function of fuel pumps to actively transfer the fuel out of the tank. When the pumps are turned OFF, they cease to create the necessary pressure and flow required to jettison fuel. This means that without the pumps engaged, gravity alone is typically insufficient to allow the fuel to exit the tank in a controlled manner. In many aircraft designs, especially those with complex fuel management systems, the jettisoning function is integrated with the operation of the fuel pumps. Therefore, turning the pumps OFF effectively disables the ability to jettison fuel from the center tank. This is critical for maintaining safe operations, as jettisoning fuel is often a process used to reduce weight during specific flight conditions, such as when returning to land shortly after takeoff. Understanding this principle is vital for ensuring that pilots and flight crews can manage fuel resources, maintain operational safety, and comply with flight regulations regarding fuel management.