What does 'Arm' in the WAM formula refer to?

In the WAM (Weight and Moment) formula, 'Arm' specifically refers to the distance from a designated reference point, often the datum, to the center of gravity (CG) of the aircraft. This measurement is crucial because it helps in determining the moments acting on the aircraft, which are essential for balance and stability.

The arm is an important component that, when multiplied by the weight, gives the moment contributing to the overall stability of the aircraft during flight. Understanding the arm helps pilots and aircraft operators calculate weight and balance, crucial for safe flight operations.

The other concepts mentioned, such as total weight, moment created by lift, and force applied on the wings, are fundamental to understanding aircraft dynamics and performance, but they do not specifically define what 'Arm' represents in the context of the WAM formula.