Which would have an effect on aircraft CG results when conducting a weight and balance check?

• A. Leaving the downlocks installed.
• B. Using a different fuel brand.
• C. Changing the color of the paint.
• D. Increasing cabin lighting.

Answer: (A)

CG is about where the total weight acts, which depends on both how much weight there is and where that weight is located relative to the datum. Any added weight at a fixed location shifts the moment and, therefore, the calculated CG.

Leaving the downlocks installed changes the airplane’s weight and the moment because those components add mass at their specific position. If they’re left in place during a weight-and-balance check, the result will reflect that extra weight and sit at a different arm, altering the CG calculation. In practice, you’d remove nonessential items like downlocks (or account for them explicitly) to obtain an accurate CG for flight.

The other options don’t meaningfully affect CG for a typical check: different fuel brands have essentially the same weight per volume, so the mass doesn’t change CG in a practical sense; paint color and cabin lighting add negligible weight and don’t shift the CG in any meaningful way.