The bi-directional XFLOW pump turns on and auto XFLOW begins when the fuel imbalance reaches how many pounds?

• A. 100 pounds.
• B. 150 pounds.
• C. 200 pounds.
• D. 250 pounds.

Answer: (C)

When fuel is split between the left and right wing tanks, the system monitors the imbalance and uses a crossflow pump to move fuel from the heavier wing to the lighter wing to keep the aircraft’s center of gravity in safe limits. The auto XFLOW feature is designed to start at a defined imbalance, which for this system is 200 pounds. That threshold provides a practical balance: it avoids needless pumping for small differences, but responds quickly enough to prevent the CG from drifting too far. Because the pump is bi-directional, it can move fuel in either direction to restore balance efficiently. Imbalances much smaller (like 100 pounds) would trigger unnecessary pumps, while waiting until 250 pounds could let the aircraft operate with a riskier balance. Therefore, 200 pounds is the correct activation point.