What is a "moment arm" in aviation?

A moment arm in aviation refers to the distance from a specified reference point (often the center of gravity) to the location of a weight on the aircraft. It is a crucial concept in understanding how weight distribution affects the aircraft's balance and stability. The moment arm affects the lever arm principle in which the farther the weight is from the center of gravity, the greater the moment that weight will create, impacting the aircraft's control and handling characteristics.

This understanding is vital for pilots and aircraft maintenance personnel emphasizing proper weight and balance calculations to ensure safe and efficient operation of the aircraft. By knowing where a weight is located and its distance from the center of gravity, one can predict how it will affect the aircraft’s performance and stability during flight.