What document certifies an aircraft's airworthiness?

The Certificate of Airworthiness is the key document that certifies an aircraft's airworthiness. This document is issued by the relevant aviation authority, such as the FAA in the United States, and it indicates that the aircraft meets all safety and design standards set forth by the regulatory body. It confirms that the aircraft has been inspected, that all necessary maintenance has been performed, and that it is deemed safe for flight.

This certificate is crucial for ensuring that the aircraft complies with all applicable regulations and is fit for operational use. It is generally required before an aircraft can be legally flown and is a key factor in maintaining the aviation safety standards across the industry.

In contrast, a Bill of Sale provides proof of ownership but neither addresses the airworthiness of the aircraft nor serves as a certification. The Registration Certificate, while essential for identifying the aircraft as legally registered, does not speak to its operational safety or maintenance status. Maintenance Records document all the maintenance activities performed on the aircraft but do not independently certify airworthiness; they are vital for tracking the aircraft's condition over time and can support airworthiness, but they themselves are not a certification.