How is the center of gravity (CG) of an aircraft determined?

The center of gravity (CG) of an aircraft is determined by summing the moments of all the individual weights relative to a reference point (usually the datum) and then dividing that total moment by the total weight of the aircraft. This method calculates the CG mathematically, allowing for precise location of the CG based on the distribution of weight from passengers, cargo, fuel, and other factors.

The calculation involves considering each weight's distance from the reference point to determine its moment (weight multiplied by its arm relative to the datum). After calculating the total moments for all items, it is divided by the total weight to provide the CG location, usually expressed in inches from the datum.

This method is essential since it accurately reflects how weight distribution affects the overall balance and stability of the aircraft during operations. It helps pilots ensure that the aircraft is within safe loading limits and can perform effectively during flight.

The other options do not accurately reflect how the CG is determined. For instance, averaging weights does not account for their distribution or leverage, using fuel gauges provides no actual CG calculation, and conducting a flight test measures performance rather than calculating CG directly.