What document provides evidence of aircraft registration?

The document that provides evidence of aircraft registration is the Certificate of Registration. This certificate is officially issued by the aviation authority of the country in which the aircraft is registered. It contains specific details about the aircraft, including its make, model, serial number, and the name of the registered owner. This document is crucial because it serves as legal proof that the aircraft is registered and complies with the necessary regulations.

In contrast, the technical log is used for recording details about the aircraft's maintenance and flight operations, but it does not serve to confirm registration status. A radio operator’s certificate is related to the operation of radio communication equipment on board the aircraft, and it does not pertain to the aircraft's registration. Similarly, a flight plan is a document that pilots file with air traffic control regarding their intended route of flight, but it also does not provide any evidence of the aircraft's registered status. Hence, the Certificate of Registration is the clear and definitive choice for evidence of aircraft registration.