What is the Balance Arm (BA)?

The Balance Arm (BA) is defined as the distance from the datum to the centre of gravity of a mass. This concept is important in aviation as it relates to the stability and control of an aircraft. The balance arm effectively measures how far the centre of gravity (CG) of the aircraft is in relation to a reference point, known as the datum. Understanding this distance is vital for calculations related to weight and balance, which play a critical role in ensuring safe flight operations.

When the position of the centre of gravity moves relative to the datum, it affects the aircraft's moment about that datum and, consequently, its balance. Knowing the balance arm allows pilots and planners to make informed decisions regarding load distribution, which ensures that the aircraft remains within its safe operating parameters. This knowledge is essential for maintaining proper control and stable flight dynamics.