Airman Certification Standards (ACS)
The FAA-S-ACS-1 Aviation Mechanic General, Airframe, and Powerplant Airman Certification Standards define what an applicant must know, understand, and demonstrate for the FAA mechanic knowledge, oral, and practical tests.
General Subject Areas
Foundation knowledge required before Airframe or Powerplant testing.
Airframe Subject Areas
Structures, systems, inspections, repairs, and airframe maintenance tasks.
Powerplant Subject Areas
Engines, systems, propellers, fuel, ignition, lubrication, and troubleshooting.
The ACS Is Your Testing Roadmap
The mechanic ACS organizes the required knowledge, risk management, and skill elements for the FAA Aviation Mechanic certificate. It applies to the written knowledge tests, oral questioning, and practical evaluation.
The General test must be completed before the Airframe or Powerplant rating. For best results, study in order: General first, then Airframe, then Powerplant.
1. Study the ACS Areas
Use the ACS subject areas to understand what the FAA expects you to know, explain, and apply.
2. Practice by Test Section
Work through General, Airframe, and Powerplant practice questions until your weak areas are clear.
3. Review Missed Codes
After testing, use your ACS report codes to target oral and practical prep with your instructor.
⚠ Instructor Tip
Do not memorize answers only. Use the ACS to understand the FAA reference, the aircraft system logic, and why incorrect answers are wrong.