Definition
The reference datum is an imaginary vertical plane used for balance and Centre of Gravity (CG) calculations in aircraft. This plane serves as the starting point for measuring all horizontal distances on the aircraft.
Description
Manufacturers define the reference datum for each aircraft type. It can be located at a specific station on the aircraft or, more commonly, at a set distance in front of the aircraft’s nose. This positioning helps simplify CG calculations. Arms and moments, which are crucial for understanding balance, are calculated based on this reference datum.
