The ________ is located in the collector tank and ensures an uninterrupted fuel supply to the engine during inverted flight operations.

The flip-flop valve is a critical component located in the collector tank of the T-6B aircraft's fuel system. Its primary function is to maintain an uninterrupted fuel supply to the engine, particularly during inverted flight or situations where the aircraft may experience negative G-forces.

During these conditions, fuel has a tendency to move away from the fuel inlet points due to gravitational forces. The flip-flop valve is designed to allow for the redistribution of fuel within the collector tank, ensuring that the engine continues to receive fuel even when the aircraft is inverted. This capability is essential for maintaining engine operation and overall flight safety during aerobatic maneuvers or any flight situation that may lead to a temporary disruption in fuel flow.

In contrast, the defuel valve primarily functions to control the defueling process and does not play a role in maintaining fuel supply during flight. The engine-driven low-pressure fuel pump is responsible for providing fuel from the collector tank to the engine but relies on fuel being available in that tank. The electric boost pump is used to assist in fuel delivery, especially during starting and low fuel flow situations, but it doesn't have the same critical role in managing fuel during inverted flight as the flip-flop valve does.