When must an aircraft be re-weighed?

An aircraft must be re-weighed if the change in weight is more than 2% of the empty weight to ensure that its operating specifications are accurate and reflect its current configuration. This requirement is based on regulatory guidance to maintain safety and performance standards.

Re-weighing the aircraft after a significant weight change helps pilots and operators to correctly calculate performance metrics such as takeoff weight, landing weight, and balance. These calculations are crucial for safe operation, as they impact flight characteristics and compliance with weight limits.

The emphasis on a 2% threshold is specifically intended to account for even minor modifications or changes in equipment that could cumulatively affect the weight beyond a small margin, ensuring the aircraft's data remains current and reliable for use. This practice contributes to the overall safety management of the flight operation and is a standard compliance measure in aviation.