All the limitations and the definitions related to weight and balance aspects use what is called the Mean Aerodynamic Chord (MAC) or the reference chord (RC). For example, the position of the center of gravity (CG) is usually expressed in terms of percentage (%) of MAC. The safe limits for the CG are also expressed in terms of percentage (%) of MAC (the symbol used is %MAC)
The MAC is a reference line used in the design of the wing; its position relative to the wing and the fuselage is accurately known. The position and dimensions of this reference line are mentioned in the Weight and Balance Manual (WBM)
Author – Zinhom Mahmoud
Aviation Training Consultant at EgyptAir
