Which items should be accounted for when calculating weight and balance?

When calculating weight and balance for an aircraft, it's essential to account for all factors that can influence the aircraft's total weight and its center of gravity. Optional equipment is a critical item in this calculation because it directly affects both the weight and the distribution of weight within the aircraft.

Optional equipment refers to any additional items that can be installed or removed from the aircraft, such as extra passenger seats, avionics, or other modifications. These items can significantly affect the overall weight and balance of the aircraft, and because they are not standard in every configuration, their presence must be explicitly accounted for in the calculation.

When optional equipment is added, it increases the total weight and may shift the center of gravity, which is crucial for the safe operation of the aircraft. Pilots need to ensure that the added equipment does not exceed the aircraft's maximum weight limit and that the center of gravity remains within specified limits for safe flight operations. Therefore, neglecting optional equipment in weight and balance calculations could lead to dangerous flight conditions.

While usable and unusable fuel are also important for flight operation and performance considerations, they may not be considered optional equipment, as the specific situation regarding their weight may vary depending on the mission.