How is the total weight of an aircraft determined?

The total weight of an aircraft is accurately determined by summing the basic empty weight, which includes the weight of the aircraft structure and all fixed equipment, with the payload and fuel. The basic empty weight serves as the starting point, and to assess the aircraft's operating weight, you must add the weight of any cargo, passengers, and the fuel that will be consumed during flight. This total weight is crucial for ensuring that the aircraft operates within safe limits and adheres to performance calculations required for takeoff, landing, and maneuverability.

In this context, merely measuring pilot and passenger weight overlooks essential components like fuel and cargo, leading to an incomplete picture of the aircraft's total weight. Additionally, the weight of the empty fuel tanks alone does not represent the total weight, as it ignores all other significant weight factors. Relying on the gross weight indicated during takeoff could be misleading, as it may not provide a clear understanding of the build-up to that weight without considering the individual components that contribute to the overall weight calculation.