What is the relationship of usable fuel to the aircraft's weight during flight?

Usable fuel is a crucial component in weight and balance calculations for aircraft. During flight, the amount of fuel on board directly impacts the aircraft's total weight, which subsequently affects performance, stability, and safety. Weight and balance calculations are essential to ensure the aircraft operates within its established limits, helping to maintain an optimal center of gravity and performance.

In these calculations, usable fuel is included as it represents a significant portion of the aircraft's weight. Accurate weight and balance assessments ensure that the aircraft can be safely flown, avoiding issues such as overloading or improper loading that could compromise flight safety. Therefore, including usable fuel in weight and balance calculations is fundamental to safe aircraft operation.