The bi-directional XFLOW pump turns on when the fuel imbalance between wing tanks reaches how many pounds?

• A. 100 lbs
• B. 300 lbs
• C. 400 lbs
• D. 200 lbs

Answer: (D)

The key idea is how fuel balance between the wings is maintained to keep the aircraft stable. The bi-directional XFLOW pump moves fuel from the heavier wing to the lighter one to equalize the tanks, helping keep the center of gravity where it should be. It’s designed to start automatically when the imbalance between wing tanks reaches a specific threshold. That threshold is set so the system activates only when the difference is significant enough to affect handling, but not so small that the pump would run constantly. Once it starts, it continues to move fuel to bring the imbalance back toward a safe level and then stops automatically. In this scenario, the threshold described is a mid-range imbalance value, which provides timely correction without premature operation.