In a Weight and Balance calculation, what does 'ARM' stand for?

In the context of Weight and Balance calculations, "ARM" specifically refers to "Aircraft Reference Moment." This term is critical in the process of determining the center of gravity (CG) of an aircraft, which is essential for safe flight operations. The ARM is essentially the distance from a reference point, usually the aircraft's datum, to the location of a specific weight within the aircraft. By using ARMs along with the weights of various components (such as passengers, cargo, and fuel), engineers can compute the moment, represented as the weight multiplied by the arm. This value helps establish how the distribution of weight impacts the overall balance and stability of the aircraft during flight. Proper understanding and calculation of these measurements are vital to ensure that the aircraft remains within safe operating limits.