Which statement correctly describes ballast movement and its effect on CG?

• A. A ballast load placed aft will move the CG toward the aft limit.
• B. Moving ballast toward forward stations moves CG forward and toward aft stations moves CG aft.
• C. A ballast load placed forward will move the CG toward the forward limit.
• D. Ballast has no effect on CG.

Answer: (B)

The key idea is that ballast changes the CG by changing where a portion of the aircraft’s weight sits along the longitudinal axis. The CG is the weighted average of all weights, so moving ballast toward the front (forward stations) lowers its arm and shifts the overall moment in a forward direction; moving ballast toward the back (aft stations) increases its arm and shifts the moment aft. In other words, the CG tends to move toward the new location of the ballast.

This is why the correct statement describes moving ballast forward shifting the CG forward and moving ballast aft shifting the CG aft. Ballast does affect CG; the exact amount of shift depends on how much ballast is moved and where, and you must ensure the final CG stays within the approved limits.