Which document must be carried on board the aircraft, evidencing its regulatory compliance?

The Aircraft Certificate of Registration is a crucial document that must be carried on board an aircraft to demonstrate regulatory compliance. It serves as proof that the aircraft is registered with the appropriate national authority, which is essential for legal operation. This Certificate includes vital information such as the aircraft's registration number, the owner's details, and confirmation that the aircraft complies with the necessary regulations for airworthiness and operation.

While other documents serve important roles in aviation—such as the Flight Operations Handbook, which provides guidance on operating procedures, and the Airworthiness Certificate, which indicates that the aircraft meets safety standards—they do not specifically fulfill the requirement of evidencing registration compliance. The Aircraft Registration Manual, though informative, is not typically carried on board and does not serve as regulatory proof in the same way the Certificate of Registration does. Thus, possessing the Aircraft Certificate of Registration is essential for legal and operational verification while the aircraft is in flight.