Which factor is essential when calculating the aircraft's center of gravity?

When calculating an aircraft's center of gravity (CG), it is essential to consider the total weight of onboard equipment. The center of gravity is determined by the distribution of weight throughout the aircraft, including passengers, luggage, fuel, and any cargo. Each of these components contributes to the overall balance and stability of the aircraft.

The total weight of onboard equipment directly affects how the CG is positioned relative to the aircraft's design specifications. An accurate calculation requires incorporating all relevant weights to ensure the aircraft remains within its operational limits and guarantees safe flight performance.

In context, while the weight of the pilot is a factor, it is just one component among many that contribute to the total weight. Fuel types may influence performance and operational efficiency but do not directly contribute to the center of gravity calculation. The wing loading ratio relates to how weight is distributed across the wing area but does not provide a direct measure of CG. Thus, the total weight of onboard equipment is crucial for accurately determining the aircraft's center of gravity.