Which condition is a trigger for reweighing the aircraft due to weight and CG concerns?

• A. Modification of components greater than 1% of basic weight
• B. Repainting the exterior
• C. Replacing the seats
• D. Upgrading radios

Answer: (A)

Weight and balance data must reflect any change that could move the airplane’s weight or center of gravity. If a modification changes the basic empty weight by more than a small amount, you must reweigh and update the weight-and-balance records. The standard threshold used is 1% of the basic empty weight, so only changes that exceed that amount require reweighing. Repainting the exterior is cosmetic and adds very little weight, well below that threshold, so it doesn’t trigger reweighing. Replacing seats or upgrading radios could affect weight, but again only if the total change surpasses the 1% limit; otherwise the existing weight-and-balance data remains valid. So the condition that triggers reweighing is modification of components greater than 1% of basic weight.