If you have a forward shift in weight, what general trend do you expect in the CG value?

• A. The CG value will move forward (to a smaller inch value).
• B. The CG value will move aft (to a larger inch value)
• C. The CG value will remain unchanged
• D. The CG will become undefined

Answer: (A)

CG is the weighted average location of all weights along the airplane’s longitudinal axis, measured as inches forward of a fixed datum. When weight is shifted toward the nose, that weight has a smaller distance (arm) from the datum than the weights farther aft, so the overall weighted average moves toward the front. In the standard inches-forward-of-datum convention, moving weight forward reduces the numerical CG value, meaning the CG shifts forward to a smaller inch value. A quick way to picture it: CG = (sum of weight × arm) / total weight. If you relocate some weight from a location with a larger arm to a location with a smaller arm, the numerator drops relative to the total, pulling the CG value forward.