Which source contains approved data for performing a major repair to an aircraft engine?

The correct answer is based on the fact that major repairs to an aircraft engine must be executed in accordance with data that is officially recognized and approved. Manufacturer's maintenance instructions are integral to this process; when these instructions are FAA approved, they provide detailed guidance that has been evaluated for safety and compliance with regulatory standards. This approval signifies that the data meets the necessary criteria for performing repairs on certified aircraft, ensuring that safety and operational specifications are upheld.

While service bulletins and FAA advisory circulars can provide valuable information and recommendations, they may not necessarily have the same level of regulatory approval required for major repairs. Service bulletins often offer updates or preventative measures but do not always equate to approved data for major modifications or repairs. Local FAA branch guidelines may be informative but lack the specificity and official approval needed for major repair work on aircraft engines.