Which method can provide the empty weight of an aircraft if the weight and balance records are lost or destroyed?

Reweighing the aircraft is the most reliable method for determining its empty weight if the weight and balance records are lost or destroyed. This process involves physically weighing the aircraft and requires using calibrated scales that can accurately measure the weight of the aircraft in its standard configuration (without any payload, passengers, or fuel).

This method is considered the gold standard because it reflects the actual weight of the aircraft as it currently exists, factoring in any modifications or changes that may have occurred over time. The weight can vary due to installations of additional equipment, repairs, or even differences in materials, making empirical measurement the most trustworthy approach.

Other options may fall short for various reasons. Estimating based on size could lead to inaccuracies as it does not account for the specific configuration, modifications, or materials used, which can significantly affect weight. Relying solely on the manufacturer’s specifications might be misleading, especially if the aircraft has undergone changes since it was built. Comparing with similar aircraft might also lead to incorrect assumptions because variations in equipment and configuration can result in different weights.

Thus, reweighing the aircraft provides the most accurate means of finding its empty weight under such circumstances.