Which entity is typically responsible for approving modifications and certifying compliance for airworthiness?

• A. Competent authority (regulatory authority)
• B. Aircraft manufacturer only
• C. Insurance company
• D. No approval required

Answer: (A)

The key idea is that airworthiness modifications must be approved by the regulatory authority that oversees aviation safety. This competent authority reviews any changes to an aircraft—such as major repairs, structural modifications, or equipment updates—to ensure they meet the applicable airworthiness standards and certification basis. They evaluate the provided data (design, testing, and conformity of parts), may require inspections or testing, and then issue the appropriate certification or approval, such as an airworthiness certificate, an amendment to the type certificate, or a supplemental type certificate. The aircraft manufacturer can supply the design data and support the process, but the final approval rests with the regulator to ensure consistent safety across the fleet. An insurance company does not grant airworthiness certification, and claiming that no approval is required is incorrect because safety-critical changes must be officially cleared before operation.