14 CFR § 65.79

Each applicant for a mechanic certificate or rating must pass an oral test and a practical test, as appropriate to the rating sought, by demonstrating satisfactory understanding of the knowledge, risk management, and skill elements for each subject contained in the Aviation Mechanic General, Airframe, and Powerplant Airmen Certification Standards (incorporated by reference, see § 65.23), as appropriate to the rating sought.