How can fuel distribution in a multi-tank wing affect CG during flight, and how is it mitigated?

• A. It cannot affect CG.
• B. Uneven fuel distribution shifts CG; balance by distributing fuel evenly, or using counterweights or ballast, and re-check CG after fuel changes.
• C. It only affects airspeed, not CG; mitigate by reducing power.
• D. It shifts the center of gravity aft permanently; fix by landing and reloading.

Answer: (B)

Fuel in multiple wing tanks changes where the aircraft’s mass is concentrated. If one wing carries more fuel than the other, the heavier side pulls the center of gravity toward that wing, creating a lateral CG shift that can cause a roll tendency and move you away from the approved balance range. As fuel is burned, the distribution can change again, so the CG can drift midflight if the consumption isn’t balanced.

To keep the airplane controllable and within limits, you balance the fuel across the tanks. This can mean transferring fuel between wings, using crossfeed to equalize the load, and, if needed, adding ballast or counterweights to maintain symmetry. After any change in fuel—refueling, transfer, or unequal consumption—you recalculate and verify the CG to ensure it remains within the permitted envelope. This combination of even distribution and verification is how the risk of CG drift is mitigated.