Overview of the FAA Knowledge Testing Program

The FAA knowledge tests for mechanics — officially the Aviation Mechanic General (AMG), Airframe (AMA), and Powerplant (AMP) tests — are the written component of A&P certification. They are delivered by PSI Services at hundreds of computer-based testing centers across the United States. The tests are aligned with the Aviation Mechanic Airman Certification Standards (FAA-S-ACS-1), the FAA's official document defining every subject area and task you must master.

The ACS is not a textbook in itself — it is a standard that lists subject areas, tasks, knowledge elements, and risk elements you are expected to know. Candidates use the FAA AMT Handbooks (FAA-H-8083-30 General, -31 Airframe, -32 Powerplant), 14 CFR regulations, AC 43.13-1B, and exam preparation platforms to cover the material. Understanding the structure of the ACS is the first step to efficient exam preparation.

Registration is done online through the PSI FAA testing portal using your FAA tracking number (FTN). You create a PSI account, select your test (AMG, AMA, or AMP), pay the fee, and schedule a session at a convenient test center. On exam day, arrive 30 minutes early with a government-issued photo ID and your PSI confirmation.

Test 1: General (AMG)

Questions: 60 | Time: 2 hours | Pass mark: 70%

The General test covers the foundations every mechanic needs regardless of rating. It is the prerequisite for both the Airframe and Powerplant ratings, and the regulations portion is one of the most challenging sections — regulatory language is dense and precise, and questions frequently test nuance rather than rote memorization.

Key subject areas covered:

Regulations and Publications (14 CFR) — Part 43 maintenance rules, Part 65 mechanic certification and privileges, Part 91 inspections and records, Part 39 Airworthiness Directives, and the role of AC 43.13-1B, FAA Form 337, and the AMT Handbooks. This is the most heavily tested General subject area.
Mathematics and Physics — Arithmetic, algebra, geometry, ratios and percentages, force, work, power, and simple machines. Weight & balance calculations appear in their own subject area.
Basic Electricity — Ohm's law, Kirchhoff's laws, AC/DC theory, inductance, capacitance, impedance, and power calculations. Series and parallel circuits.
Aircraft Drawings — Blueprints, schematic diagrams, wiring diagrams, symbols, and title block information.
Weight and Balance — Empty weight and center of gravity determination, loading computations, and weighing procedures.
Materials and Processes — Aircraft metals, composites, wood, fabric, heat treatment, and fastener identification.
Fluid Lines and Fittings — Rigid and flexible lines, fittings, hoses, and fabrication and installation standards.
Cleaning and Corrosion Control — Corrosion types, prevention, and treatment.
Ground Operations and Servicing — Ground handling, fueling, towing, jacking, and safety practices.
Mechanic Privileges and Limitations — Return-to-service authority under §43.7, inspection authority, and rating limits.
Human Factors — Fatigue, stress, complacency, and the "dirty dozen" of maintenance errors.

For a deeper dive into the regulations portion specifically, including practice questions and study strategies, see our dedicated FAA regulations guide.

Test 2: Airframe (AMA)

Questions: 100 | Time: 2 hours | Pass mark: 70%

The Airframe test evaluates your knowledge of aircraft structures and non-engine systems. It requires a thorough understanding of how airframes are designed, built, inspected, and repaired.

Key subject areas covered:

Airframe structures — Wood structures, fabric covering and finishes, sheet metal and non-metallic (composite) structures, welding, assembly and rigging, and airframe inspection. Materials science and NDT methods (dye penetrant, magnetic particle, eddy current, ultrasonic).
Aircraft electrical systems — Wiring, connectors, circuit protection, bonding and grounding, and electrical load analysis.
Instrument systems — Pitot-static systems, gyroscopic instruments, electronic flight instruments, and system testing.
Communication and navigation systems — VHF, VOR, ILS, DME, ADF, GPS, transponders, and weather radar.
Hydraulic and pneumatic power systems — Pumps, actuators, valves, accumulators, filters, fluids, and bleed air systems.
Landing gear systems — Fixed and retractable gear, shock struts, brakes, wheels, tires, anti-skid, and nosewheel steering.
Fuel systems — Tanks, pumps, valves, quantity indicating systems, and fueling procedures.
Environmental systems — Pressurization, air conditioning, heating, and oxygen systems.
Fire protection systems — Fire and smoke detection and extinguishing systems.
Ice and rain control — Pneumatic boots, electro-thermal anti-icing, windshield protection, and rain removal.
Flight control systems — Primary and secondary controls, actuation systems, trim, and control surface balancing.

Test 3: Powerplant (AMP)

Questions: 100 | Time: 2 hours | Pass mark: 70%

The Powerplant test covers both reciprocating (piston) engines and turbine engines, plus propellers. It is widely considered the most demanding of the three tests — engine theory requires both memorization and conceptual understanding of thermodynamics and mechanical systems.

Key subject areas covered:

Reciprocating engines — Four-stroke cycle theory, engine components (cylinders, pistons, crankshafts, valves), valve timing, ignition timing, and power output. Engine configurations and the factors affecting performance.
Turbine engines — Gas turbine theory, engine types (turbojet, turbofan, turboprop, turboshaft), compressor types (axial, centrifugal), combustion chambers, turbine sections, and exhaust systems. Thrust reversers and engine health monitoring.
Engine inspection — Compression testing, borescope inspection, and engine condition monitoring for both engine types.
Engine instrument systems — RPM, temperatures (EGT, TIT, CHT), pressures, fuel flow, torque, and vibration monitoring.
Ignition and starting systems — Magnetos, igniters, ignition harnesses, timing procedures, and starter systems.
Lubrication systems — Wet sump and dry sump systems, oil types, filters, coolers, and oil analysis.
Fuel metering systems — Carburetors, fuel injection, fuel control units, and FADEC.
Engine fuel, induction, cooling, and exhaust systems — Components, maintenance procedures, and inspection criteria.
Propellers — Fixed-pitch and constant-speed propellers, feathering and reversing, governors, synchronization, tracking, balancing, and inspection.

What Happens on Exam Day

On the day of your test, arrive at the PSI test center at least 30 minutes early. The check-in process is straightforward:

Identification — Present a valid, government-issued photo ID (driver's license, passport, or military ID) that matches your registration. You will also be asked for your FAA tracking number.
Security — Test centers require you to sign in, store personal belongings (phone, smartwatch, notes, calculators) in a locker, and sometimes submit to a palm-vein scan or photo for identity verification. No electronic devices are allowed in the testing room.
The testing room — You are assigned a computer workstation. A whiteboard or scratch paper and a basic calculator are typically provided. The test software includes a timer and flags questions for review.
During the test — You may not bring reference materials — the test is closed-book. The 2-hour clock runs continuously, though you can take a break if needed (the clock does not stop).
Results — Your score appears on screen immediately after you submit, and you receive an official Airman Knowledge Test Report showing your score and performance by subject area. Keep this report — you will need it for the oral and practical test.

Oral and Practical Exam

The written tests are only part of the certification process. After passing your knowledge tests and completing your experience requirements (or graduating from a Part 147 school), you must pass the oral and practical exam administered by a Designated Mechanic Examiner (DME).

Oral exam: The DME asks probing questions across the entire ACS, focusing on your ability to apply knowledge to real-world scenarios. Unlike the multiple-choice written tests, the oral exam requires you to articulate your reasoning, demonstrate genuine understanding, and show that you can think critically about maintenance problems.

Practical exam: You perform maintenance tasks under direct observation. The DME evaluates your technique, safety awareness, use of approved data, tool control, and compliance with regulatory requirements. Common tasks include inspecting a component, interpreting a technical publication, diagnosing a simulated fault, or completing a maintenance record entry. You must present your FAA Form 8610-2 (Airman Certificate and/or Rating Application) and knowledge test reports at the start of the session.

Preparation for the oral and practical exam requires a different approach than the written tests. Focus on understanding the "why" behind procedures, not just the "what." Practice explaining your reasoning out loud. Review your experience documentation thoroughly so you can speak confidently about it. Consider doing mock oral exams with experienced A&P mechanics to build confidence.

Exam Scoring and Passing Criteria

All FAA A&P knowledge tests use the following scoring system:

Pass mark — 70% for all three tests.
Scoring — Each correct answer earns you one point. There is no penalty for incorrect answers, so never leave a question unanswered.
Exam format — Multiple-choice questions with four options. Some questions include figures, diagrams, or charts.
Computer-based — Tests are administered at PSI testing centers on computer terminals. Results are available immediately after completion.
Retakes — If you fail a test, you can retake it by re-registering and paying the test fee again. Your test report shows your performance by subject area, so you know exactly what to study before retaking.

Proven Study Strategies for the A&P Tests

Passing the FAA knowledge tests requires more than just reading the material. Here are strategies used by successful candidates:

Start with the General test — The foundational knowledge from AM.I underpins both technical tests. Master it first, and the Airframe and Powerplant tests become significantly easier.
Use the ACS as your checklist — Download the Aviation Mechanic ACS and check off tasks as you study each one. This ensures you don't miss any subject area or knowledge element.
Active recall over passive reading — Reading textbooks creates familiarity, not mastery. Use practice questions, flashcards, and self-quizzing to build genuine recall.
Focus on your weak areas — It's natural to gravitate toward topics you already understand. Use a platform like Sky License that identifies your weak subject areas and forces you to practice them.
Simulate exam conditions — Take timed practice exams in a quiet environment. This builds speed, endurance, and familiarity with the question format.
Study in spaced sessions — Short, frequent study sessions (45–60 minutes) are more effective than marathon sessions. Spaced repetition helps transfer knowledge from short-term to long-term memory.
Join study groups — Discussing topics with fellow A&P candidates reveals gaps in your understanding and exposes you to different perspectives on the same material.

How Sky License Prepares You for Exam Day

Sky License is purpose-built for FAA A&P exam preparation. Our AI-powered platform covers every subject area in the Aviation Mechanic ACS.

Complete ACS coverage — All three tests with thousands of practice questions mapped to specific ACS tasks.
Adaptive AI technology — The platform identifies your weak areas and adjusts question difficulty in real time, maximizing every minute of study time.
Real exam simulations — Timed exams that replicate the official PSI testing environment, including question formats and time constraints.
AI Tutor — Get instant, syllabus-referenced explanations for any topic. Ask follow-up questions until you truly understand.
Progress analytics — Detailed performance tracking across every subject area shows exactly where you need more study.

Start preparing with Sky License →