When can a holder of an inspection authorization approve a major repair recorded on an FAA Form 337?

The holder of an inspection authorization (IA) can approve a major repair recorded on an FAA Form 337 when a major repair is supervised by a certificated mechanic. This is important because the IA's role requires thorough oversight and adherence to regulations. The supervision by a certificated mechanic ensures that the major repair meets the necessary standards and that the work is conducted under the guidance of someone with the appropriate qualifications.

This context is pivotal since major repairs often involve significant changes to an aircraft's structure or systems, which can affect safety and compliance with airworthiness standards. The IA’s approval signifies that the repair work has been adequately reviewed, observed, and conforms to the required specifications.

Other options suggest conditions under which major repairs might be approved, but they do not address the requirement of supervision by a certificated mechanic. While the detailed description of a repair and relevant data from the manufacturer are important for the repair process, they do not replace the need for direct oversight to ensure compliance and quality assurance during the repair activity. The emphasis on supervision reflects the regulatory priorities as established by the FAA to maintain safety in aviation operations.