Free EASA Part-66 Practice Questions

✅ Correct Answer: B: Certifying staff holding the appropriate Part-66 licence category and, where required, the relevant type rating for that aircraft

Under Part-66 (66.A.20) and Part-M (M.A.801), the CRS must be signed by certifying staff holding the appropriate licence category (A, B1, B2 or B3) and, where applicable, the relevant aircraft type rating. The licence privileges define which aircraft and tasks the certifying staff may sign for.

Reference: Regulation (EU) No 1321/2014 — Part-66 66.A.20, Part-M M.A.801

✅ Correct Answer: A: The EASA Form 1 (authorised release certificate)

The EASA Form 1 is the authorised release certificate used to certify that a component (part, appliance or material) has been released to service in accordance with approved data. The CRS is used for the aircraft as a whole, while the ARC certifies continuing airworthiness after an airworthiness review.

Reference: Regulation (EU) No 1321/2014 — Part-M Appendix II (EASA Form 1)

✅ Correct Answer: C: 75%

Every Part-66 basic knowledge module examination requires a pass mark of 75% (66.A.25). This is higher than many other licensing systems — the FAA knowledge tests, for example, require only 70%. On Module 10 (64 questions), 75% means at least 48 correct answers.

Reference: Regulation (EU) No 1321/2014 — Part-66 66.A.25

✅ Correct Answer: C: Category B2 (avionics)

Category B2 covers avionics systems — electrical, electronic, instrument and communication/navigation systems. B1 covers the mechanical side (airframe, engines, mechanical systems), A covers limited line maintenance tasks, and B3 is specific to non-pressurised piston-engine helicopters.

Reference: Regulation (EU) No 1321/2014 — Part-66 66.A.20, Appendix I

✅ Correct Answer: A: Twelve common human error conditions such as fatigue, stress, complacency, lack of communication and lack of knowledge

The Dirty Dozen (developed by Transport Canada and adopted worldwide, including EASA Module 9) lists the twelve most common human error conditions in aviation maintenance: lack of communication, complacency, lack of knowledge, distraction, lack of teamwork, fatigue, lack of resources, pressure, lack of assertiveness, stress, lack of awareness and norms. Recognising them is the first step to preventing maintenance errors.

Reference: Part-66 Module 9 — Human Factors (M9.4–M9.8)

✅ Correct Answer: A: Voltage equals current multiplied by resistance (V = I × R)

Ohm\'s Law states that the voltage across a conductor is directly proportional to the current flowing through it, with the resistance as the constant of proportionality: V = I × R. Rearranged, I = V / R and R = V / I. This is fundamental to Module 3 (Electrical Fundamentals) and to all aircraft electrical system troubleshooting.

Reference: Part-66 Module 3 — Electrical Fundamentals (M3.5)

✅ Correct Answer: C: A damaged or misadjusted downlock spring or actuator mechanism

When hydraulic pressure is normal but the gear does not lock down, the mechanical downlock mechanism is the primary suspect. The downlock spring or mechanical actuator physically holds the gear in the extended position. A failed microswitch affects the indication (lights/warnings), not the actual locking function.

Reference: Part-66 Module 11 — Aeroplane Systems (M11.13 Landing Gear), AMM Chapter 32

✅ Correct Answer: A: Magnetic particle inspection

Magnetic particle inspection is the method of choice for detecting surface and near-surface cracks in ferromagnetic materials (steel, nickel). The part is magnetised and iron particles concentrate at flux leakage points around discontinuities. Ultrasonic and radiography detect internal defects, while visual inspection cannot reliably reveal fine surface cracks.

Reference: Part-66 Module 6 — Materials and Hardware (M6.10), Module 7 — Maintenance Practices (M7.4)

✅ Correct Answer: A: To increase the pressure of the incoming air before combustion

The compressor raises the pressure of the incoming air before it enters the combustion chamber. Combustion then adds heat at high pressure, and the turbine extracts energy from the hot gases — part drives the compressor, the rest produces thrust. This is the core of the gas turbine cycle covered in Module 15 (M15.4–M15.10).

Reference: Part-66 Module 15 — Gas Turbine Engine (M15.4–M15.8)

✅ Correct Answer: A: The torque value must be recalculated using the extension length formula

When an extension (crowfoot, adapter) is offset from the line of the fastener, the effective lever arm changes and the applied torque differs from the wrench reading. The reading must be corrected using the formula based on the extension length and the wrench length. In-line extensions do not change the torque value.

Reference: Part-66 Module 7 — Maintenance Practices (M7.3 Workshop Practices)