What document must be on board every flight along with the Certificate of Airworthiness?

The document that must be on board every flight along with the Certificate of Airworthiness is the Certificate of Registration. This is a crucial legal requirement that ensures the aircraft is officially registered with the appropriate aviation authority. The Certificate of Registration provides vital information regarding the ownership of the aircraft and verifies that it is legally allowed to operate.

Having both the Certificate of Airworthiness and the Certificate of Registration on board is essential for demonstrating that the aircraft meets safety standards and is recognized as a legal entity. In the event of a departure from a controlled area or during inspections, the presence of these documents helps ensure compliance with regulatory requirements.

Other documents, such as interception orders, weight and balance information, and proof of insurance, while important, do not carry the same mandatory requirement to be on board for every flight as the Certificate of Registration does. These documents serve various purposes, such as operational planning or legal coverage, but they are not required to accompany the Certificate of Airworthiness on each flight.