What must an aircraft mechanic do before returning a U.S. certificated aircraft to service after major alterations?

An aircraft mechanic must utilize FAA-approved technical data prior to returning a U.S. certificated aircraft to service after major alterations because this data provides the necessary standards, procedures, and specifications that ensure the safety and airworthiness of the aircraft. The FAA mandates that any alterations made to an aircraft, especially major ones, must comply with established regulations and technical standards outlined in the approved documentation. This helps ensure that the alterations have been properly designed, installed, and tested in accordance with industry best practices and FAA regulations.

The reliance on FAA-approved technical data helps maintain the integrity of the aircraft's systems and components, ensuring they conform to safety standards. It is a crucial step in the quality assurance process, enabling mechanics to verify that work performed meets regulatory requirements before the aircraft is deemed airworthy and returned to service. This process ensures the safety of the aircraft, the crew, and passengers.