EASA Part-66 Sample Questions: Modules M1–M17
One of the most common questions we hear from Part-66 candidates is: what do the actual EASA module exam questions look like? EASA does not publish its full question bank, which leaves many candidates guessing about question format, difficulty level, and what exactly they need to know. This article walks through realistic sample questions from across the 17 basic knowledge modules — with detailed explanations of the answers and the reasoning behind them.
Skylicence Europe Team
EASA Part-66 exam preparation specialists — helping maintenance engineers earn their aircraft maintenance licence since 2025
About These Sample Questions
These questions are designed to match the style, difficulty, and format of the actual EASA module exams. They are based on the knowledge elements defined in Part-66 Appendix I — the syllabus for the 17 modules — and drawn from the topics that are most heavily tested. Each question is multiple-choice with four options, and we have included the module reference where applicable.
Note: These are samples to illustrate question formats and reasoning strategies. For full-length practice exams covering all modules, Skylicence Europe offers a comprehensive question bank with 4,464 questions, adaptive difficulty, and detailed explanations for every answer.
M3 Electrical Fundamentals Sample Question
Question 1 (M3 — DC Circuits)
"A 28-volt DC aircraft bus supplies a load drawing 10 amperes. How much electrical power does the load consume?"
- A) 2.8 watts
- B) 280 watts
- C) 2,800 watts
- D) 18 watts
Show Answer
Answer: B
Power is calculated with the formula P = E × I (power equals voltage times current). Here, 28 volts × 10 amperes = 280 watts. This is a classic M3 question — it tests your ability to apply Ohm's law and the power formula, which are foundational to every electrical system on an aircraft. See the M3 Electrical Fundamentals knowledge elements in Part-66 Appendix I (DC circuits).
This question illustrates a key pattern in module exam questions: they test fundamentals you can compute, not just recall. Many candidates confuse watts with amps or volts, so always check the units in the answer options. M3 includes several calculation questions on every exam.
M6 Materials and Hardware Sample Question
Question 2 (M6 — Aircraft Materials)
"Which aluminium alloy is most commonly used for general-purpose aircraft structural rivets?"
- A) 1100
- B) 2117-T4
- C) 2024-T4
- D) 7075-T6
Show Answer
Answer: B
2117-T4 is the standard general-purpose rivet alloy in aircraft maintenance because it can be driven in the as-received (T4) condition and age-hardens to full strength after installation. 2024-T4 and 7075-T6 are stronger but must be heat-treated or refrigerated before driving, making them special-purpose rivets. 1100 is a soft, low-strength alloy used mainly for non-structural work. This material identification question is one of the most frequently tested items in M6 — see the M6 knowledge elements on aircraft materials and fasteners in Part-66 Appendix I.
M11 Aeroplane Structures Sample Question
Question 3 (M11 — Structures)
"What type of corrosion is most commonly found in the lap joints of aluminium aircraft fuselages?"
- A) Stress corrosion cracking
- B) Pitting corrosion
- C) Crevice corrosion
- D) Galvanic corrosion
Show Answer
Answer: C
Crevice corrosion occurs in confined spaces where moisture and contaminants become trapped — exactly the conditions found in lap joints, overlapping skin panels, and riveted seams on aluminium fuselages. While pitting corrosion can occur in similar environments, crevice corrosion is specifically associated with the tight, overlapping geometry of lap joints. The M11 and M6 exams frequently ask you to match corrosion types to specific aircraft locations and conditions. See the M11 knowledge elements on airframe structures in Part-66 Appendix I.
M11 Flight Controls Sample Question
Question 4 (M11 — Flight Controls)
"What is the primary purpose of the balance weight on an aircraft control surface such as an aileron?"
- A) To increase the control force required from the pilot
- B) To prevent flutter by keeping the centre of gravity of the control surface forward of the hinge line
- C) To return the control surface to neutral when released
- D) To increase the control surface's deflection range
Show Answer
Answer: B
Balance weights are installed to prevent control surface flutter — a destructive oscillation caused by the aerodynamic and inertial forces on the surface. By keeping the surface's centre of gravity forward of the hinge line, the weight ensures any oscillation is damped rather than amplified. Flutter prevention is a fundamental flight control design principle, and balance is inspected as part of control surface maintenance. See the M11 knowledge elements on flight controls in Part-66 Appendix I.
M11 Hydraulic Systems Sample Question
Question 5 (M11 — Hydraulic Systems)
"What is the function of an accumulator in an aircraft hydraulic system?"
- A) To increase the hydraulic fluid flow rate
- B) To store hydraulic fluid under pressure and dampen pressure surges
- C) To filter contaminants from the hydraulic fluid
- D) To convert hydraulic pressure into mechanical motion
Show Answer
Answer: B
An accumulator stores hydraulic fluid under pressure — typically using a pre-charged gas bladder or piston — so it can supply fluid during peak demand (like gear retraction) and absorb pressure surges from the pump. It also maintains system pressure when the pump is unloaded. Understanding what each hydraulic component does (pump, reservoir, accumulator, actuator, filters) is a core M11 and M13 exam topic. See the M11 knowledge elements on hydraulic power systems in Part-66 Appendix I.
M15 Gas Turbine Engine Sample Question
Question 6 (M15 — Engine Control Systems)
"What does the abbreviation FADEC stand for in modern turbine engine control systems?"
- A) Full Authority Digital Engine Control
- B) Fuel and Airflow Digital Engine Controller
- C) Full Automatic Direct Engine Control
- D) Fan and Duct Electronic Controller
Show Answer
Answer: A
FADEC — Full Authority Digital Engine Control — is the electronic system that controls all aspects of turbine engine operation, including fuel flow, starting, and thrust management, with no mechanical or hydraulic linkage from the cockpit. It replaces traditional hydro-mechanical fuel control units and is standard on virtually all modern turbine engines. FADEC questions are very common on the M15 exam. See the M15 knowledge elements on engine fuel and control systems in Part-66 Appendix I.
M17 Propeller Sample Question
Question 7 (M17 — Propellers)
"What is the function of a constant-speed propeller governor?"
- A) To feather the propeller when the engine fails
- B) To maintain a constant propeller RPM by automatically changing blade pitch
- C) To reverse propeller pitch for braking
- D) To synchronise the propellers on multi-engine aircraft
Show Answer
Answer: B
The propeller governor maintains a constant propeller RPM by automatically adjusting blade pitch — increasing pitch when RPM drops and decreasing pitch when RPM rises — using flyweights and a speeder spring to regulate oil pressure to the propeller hub. Feathering and reversing are separate functions, though many governors also manage them. Propeller governor theory is a staple of the M17 exam. See the M17 knowledge elements on propellers in Part-66 Appendix I.
M15 Gas Turbine Engine Sample Question
Question 8 (M15 — Engine Theory)
"In a gas turbine engine, what is the primary function of the compressor section?"
- A) To ignite the fuel-air mixture
- B) To increase the pressure of the air entering the combustion section
- C) To extract energy from the exhaust gases
- D) To cool the turbine blades
Show Answer
Answer: B
The compressor's job is to increase the pressure of the incoming air (compression ratio) before it enters the combustion section, where fuel is added and burned. Higher compression produces more efficient combustion and greater thrust. The turbine extracts energy from the exhaust to drive the compressor — it does not compress the air itself. Knowing the function of each turbine engine section (intake, compressor, combustor, turbine, exhaust) is essential M15 exam material. See the M15 knowledge elements on gas turbine theory in Part-66 Appendix I.
Common Question Patterns Across the Modules
Based on analysis of thousands of EASA Part-66 exam questions, several patterns emerge that can help you prepare more effectively:
- Definition questions — Expect questions that check your knowledge of specific terms, abbreviations, and component functions (like FADEC, accumulator, or balance weight). These are often the easiest marks if you have studied the module syllabus.
- Calculation questions — M1, M3, and M6 include electrical, weight and balance, and physics calculations. Practice these until they are automatic.
- Scenario-based application — 20–30% of questions present a real-world maintenance scenario and ask you to identify the correct procedure, tool, or troubleshooting step. These test applied knowledge, not just recall.
- "Most likely" and "best" questions — Many questions ask for the "most likely cause" or "best course of action." These test your ability to prioritise and reason through competing possibilities.
- Identification questions — Aircraft drawings, wiring diagrams, and component illustrations appear throughout the exams. Learn to read figure-based questions (they reference numbered figures in the exam).
How to Use Sample Questions Effectively
Simply reading sample questions and checking the answers is not enough to prepare for the real exam. Here is a proven approach:
Step 1: Try to answer each question without looking at the options. If you cannot recall the answer without prompts, you do not know the material well enough yet.
Step 2: For every question you get wrong, write down the specific Appendix I knowledge element and module reference that applies. Do not move on until you understand why the correct answer is right and the others are wrong.
Step 3: Re-test yourself on the same questions 48 hours later. If you still get them right, your brain has begun encoding the information into long-term memory. If you get them wrong, repeat Step 2.
Step 4: Use a platform like Skylicence Europe to access thousands of additional questions organised by module and knowledge element, with adaptive difficulty that automatically increases as your scores improve.
Compare Skylicence Europe with other practice test platforms →
📥 Download Free Sample Questions PDF
Get 10 realistic EASA Part-66 sample questions with detailed answer explanations in a printable PDF. Perfect for offline study.
Final Advice
The biggest mistake Part-66 candidates make with sample questions is treating them as a passive reference — reading through them once and assuming they understand the material. The candidates who pass on their first attempt actively engage with every question, look up the references, and re-test themselves until the information sticks. The questions in this article are a starting point. Build on them with structured practice, and you will walk into your exam with genuine confidence.
Related Articles