What does empty weight exclude in aviation?

Empty weight in aviation refers to the weight of an aircraft without any payload, which typically includes the airframe, installed engines, systems, and all required operating equipment. However, it specifically excludes certain elements. Pilot and passenger weight is excluded as empty weight is meant to represent the aircraft in its basic, non-operational form.

When calculating empty weight, it is important to understand that usable fuel, typified in the options listed, is also excluded from this calculation. In fact, empty weight accounts for the weight of fluids needed for operation, such as hydraulic fluid and oil, but does not include any fluid that is not usable. Similarly, installed equipment that is necessary for the aircraft to operate is part of the empty weight total, and thus does not get excluded.

Therefore, the correct understanding is that empty weight does not consider the weight of the pilot and passengers since the weight of individuals aboard an aircraft varies and is considered part of the operational weight when the aircraft is loaded for flight.