Which of the following actions can a certificated mechanic NOT perform on an aircraft?

A certificated mechanic is authorized to perform a wide range of maintenance tasks on aircraft, but there are specific limitations on the types of repairs and inspections they can sign off.

In the case of major repairs, the FAA regulations require that such repairs be performed under the supervision of a certificated repair station or by an individual with the appropriate repairman or mechanic ratings and experience. Furthermore, major repairs must be documented and often require additional oversight, which includes sign-off by a licensed repair technician or properly authorized personnel who possess the necessary credentials. This ensures that major repairs meet stringent safety and quality standards as outlined by FAA regulations.

On the other hand, a certificated mechanic is fully authorized to perform minor repairs and regular inspections, such as 100-hour inspections, as well as conducting flight tests on newly installed components, provided these actions are compliant with FAA standards. Each of these activities falls within the scope of a mechanic's training and certification, enabling them to maintain the aircraft's airworthiness effectively.