airworthiness

thumb|right|Blériot XI, civil registration G-AANG. Built in 1909 and operated by the [[Shuttleworth Collection in the United Kingdom, this is the world's oldest airworthy aircraft]]

In aviation, airworthiness is the measure of an aircraft's suitability for safe flight. Initial airworthiness is demonstrated by a certificate of airworthiness issued by the civil aviation authority in the state in which the aircraft is registered, and continuing airworthiness is achieved by performing the required maintenance actions.