Automatic fuel balancing starts at what imbalance?

• A. 50 lbs
• B. 68 lbs
• C. 90 lbs
• D. 120 lbs

Answer: (B)

Automatic fuel balancing works by monitoring the weight difference between the left and right wing tanks. When that difference becomes large enough, the system automatically transfers fuel from the heavier side to the lighter side to bring the imbalance back toward zero, helping to keep the aircraft’s weight near the centerline and maintain stable directional control.

In the PC-12 NGX, that balancing action starts when the imbalance reaches 68 pounds. Once the difference hits 68 pounds, the crossfeed/transfer pumps engage to move fuel until the imbalance is reduced below the threshold, at which point the pumps stop. This ensures balancing occurs as fuel is burned, without constant cycling, and it helps maintain good handling characteristics.