What source provides specific instructions for conducting a symmetry alignment check on an aircraft?

The aircraft service or maintenance manual is the correct source for specific instructions on conducting a symmetry alignment check on an aircraft. This manual contains the detailed procedures, specifications, and necessary equipment required to perform maintenance tasks effectively and safely. It is specifically designed to guide technicians through various checks and repairs, including alignment checks, which are essential for the aircraft's performance and safety.

While the aircraft owner's manual includes general information about the aircraft and its operations, and the pilot operating handbook provides critical operating parameters necessary for pilots, they do not typically contain the detailed technical procedures found in the service or maintenance manual. FAA regulations guide offers regulatory framework and compliance information but does not provide the step-by-step instructions necessary for conducting specific technical checks. Therefore, the maintenance manual is the authoritative source for performing a symmetry alignment check.