How does fuel burn affect the center of gravity during flight, and why is this important?

• A. It changes weight distribution and shifts the center of gravity.
• B. It has no effect on center of gravity.
• C. It reduces overall aircraft stability but not CG.
• D. It causes immediate stall.

Answer: (A)

Fuel burn changes how the airplane’s weight is distributed, so the center of gravity can move as fuel is consumed. Since fuel is stored in specific locations, removing it from those locations changes the moments about the CG, causing the CG to shift. The exact direction of that shift depends on where the remaining fuel is, but the key point is that the CG can move during flight as fuel is burned.

This movement matters because the center of gravity directly affects longitudinal stability and how much elevator authority you have to trim or pitch the aircraft. If the CG moves outside the approved limits, controllability and stall characteristics can change, making the airplane harder to control or requiring different trim and handling. Therefore, pilots plan and monitor fuel usage to keep the CG within its allowable range throughout the flight.