Airworthiness and Continuing Airworthiness
From type certificate to daily service
Airworthiness has two halves. Initial airworthiness covers design and production: type certificates, supplemental type certificates, parts approval, and the issuance of the Brazilian airworthiness certificate (Certificado de Aeronavegabilidade). Continuing airworthiness keeps that status alive through maintenance programmes, airworthiness directives, repairs and alterations, and records. Candidates must know the roles: the owner or operator is responsible for maintaining airworthiness, the maintenance organisation performs the work, and licensed maintenance personnel certify it. A classic trap is treating an airworthiness directive as advisory - ADs are mandatory and normally carry a compliance time; failing to comply grounds the aircraft regardless of how well it flies.
Records and release to service
Another tested area is the release to service after maintenance and the weight-and-balance and configuration link to the flight manual. Questions often present an aircraft with an expired inspection, an unapproved modification, or a missing record, and ask whether it may fly. The answer turns on whether the item is required by the approved maintenance programme or an AD, not on whether the defect seems minor.
Rule of thumb
No airworthiness certificate is valid unless the aircraft conforms to its approved type design and is in a condition for safe operation; every maintenance action must be recorded and released by authorised personnel. Worked example: an operator installs a cabin item not covered by any approved data. Even if harmless, the installation is an unapproved alteration; the aircraft no longer conforms to its type design, so airworthiness is compromised until approved data and a proper release are obtained.