FAA AMT Airframe Practice Exam 2025 – All-in-One Study Guide to Master Aviation Maintenance Technician Certification!

The correct answer is C. Aircraft service or maintenance manual. This is because the aircraft service or maintenance manual provides detailed instructions and procedures specific to the particular aircraft model. It is the official source of information provided by the aircraft manufacturer for maintenance tasks, including symmetry alignment checks.

Options A, B, and D are incorrect because the pilot operating handbook is more focused on the operation of the aircraft, online forums may contain unofficial or inaccurate information, and engineering textbooks may provide theoretical knowledge but not specific instructions for a particular aircraft model's maintenance procedures.