How would you perform a weight-and-balance calculation for a glider with ballast and a passenger, and what limits must be observed?

How would you perform a weight-and-balance calculation for a glider with ballast and a passenger, and what limits must be observed?

• A. Compute total weight and CG location using ballast and occupant; ensure CG remains within the aircraft’s envelope before flight.
• B. Weigh the glider only and ignore ballast and occupants.
• C. Ballast cannot affect CG in gliders.
• D. CG must be within the limits only after the flight.

Answer: (A)

Weight and balance for a glider means including every weight that affects the airplane’s center of gravity and checking that the resulting CG lies within the allowed envelope for the expected flight configuration. To do this, add up the ballast weight and its position, the passenger’s weight, and any other items, then multiply each item’s weight by its distance from the datum to get moments. Sum all moments and all weights, then divide the total moment by the total weight to find the CG. Compare this CG and the total weight to the glider’s published limits; if the CG is outside the allowed range or the weight exceeds maximum gross, adjust ballast location or amount or the passenger position and re-check. The key is that ballast and occupant do shift the CG, so you must verify the balance before flight for every configuration you might fly, not after.

Weight and balance for a glider means including every weight that affects the airplane’s center of gravity and checking that the resulting CG lies within the allowed envelope for the expected flight configuration. To do this, add up the ballast weight and its position, the passenger’s weight, and any other items, then multiply each item’s weight by its distance from the datum to get moments. Sum all moments and all weights, then divide the total moment by the total weight to find the CG. Compare this CG and the total weight to the glider’s published limits; if the CG is outside the allowed range or the weight exceeds maximum gross, adjust ballast location or amount or the passenger position and re-check. The key is that ballast and occupant do shift the CG, so you must verify the balance before flight for every configuration you might fly, not after.