Which data components are essential to compute center of gravity?

Which data components are essential to compute center of gravity?

• A. Only total weight
• B. Both total weight and total moment
• C. Only total moment
• D. Aircraft altitude and airspeed

Answer: (B)

Center of gravity is found from the ratio of the total moment to the total weight. You must know both to determine the CG, because CG = total moment / total weight. The total moment is the sum of each item's weight times its arm (the distance from the datum). Without the total weight, you can’t scale the moment, and without the total moment, you can’t locate where the weight is concentrated. Altitude and airspeed don’t enter the calculation for CG, although they can change weight over time (fuel burn, loading shifts)—the instantaneous CG relies on weight and moment.

Center of gravity is found from the ratio of the total moment to the total weight. You must know both to determine the CG, because CG = total moment / total weight. The total moment is the sum of each item's weight times its arm (the distance from the datum). Without the total weight, you can’t scale the moment, and without the total moment, you can’t locate where the weight is concentrated. Altitude and airspeed don’t enter the calculation for CG, although they can change weight over time (fuel burn, loading shifts)—the instantaneous CG relies on weight and moment.