What is the practical effect of placing a ballast load aft (larger arm) on CG?

• A. Moves the CG toward the aft limit.
• B. Moves the CG toward the forward limit.
• C. Has no effect on CG.
• D. Causes the CG to become unstable.

Answer: (A)

The key idea is that the center of gravity is the balancing point of the airplane, found from the weighted average of all loads. When you place ballast toward the tail, you’re adding weight at a larger distance from the nose, which increases the tailward moment. That shifts the CG aft, moving it closer to the aft limit.

Practically, an aft-shifted CG means the airplane becomes less statically stable in pitch and more sensitive to pitch inputs. It can make the airplane harder to recover from disturbances and narrows the usable range of loading, so you must stay within the approved weight-and-balance limits. An aft ballast also increases total weight, which affects performance like takeoff and fuel endurance, but the immediate effect on the CG location is the shift toward the tail.