EASA Part-66 Aviation Legislation Guide (Module 10)

What Is the EASA Regulatory Framework?

EASA regulates aircraft maintenance through Regulation (EU) No 1321/2014. For engineers, its annexes form the core of daily work: Annex III (Part-66) establishes the aircraft maintenance licence — the categories (A, B1.1-B1.4, B2, B3), the 17 modules of Appendix I, the experience requirements of 66.A.30, and the privileges of certifying staff; Annex II (Part-145) governs approved maintenance organisations and the Certificate of Release to Service; Annex I (Part-M) covers continuing airworthiness, including the CAMO and the airworthiness review. The training organisation framework (formerly Part-147, evolving via Regulation (EU) 2023/989) governs the approved maintenance training organisations (MTOs) that deliver the module exams.

Beyond the regulation itself, Part-66 Appendix I defines everything tested on the module exams — the 17 modules, their subject areas, and the depth levels (1, 2, 3) required for each licence category. If you know the regulation and the syllabus, you know what the EASA system expects of you as a certifying engineer.

Exam Format and Structure

• Module 10 (Aviation Legislation): 64 multiple-choice questions in 80 minutes — 75% pass mark
• Every module has a fixed quota: for example M3 Electrical Fundamentals 92 questions / 115 minutes, M6 Materials and Hardware 72/90, M7 Maintenance Practices 140/175, M11 Aeroplane Structures and Systems 120/150
• Format: Computer-based exams administered by approved maintenance training organisations (MTOs)
• Pass mark: 75% on every module exam (66.A.25)
• Language: English
• Practical side: Experience and assessments per 66.A.30, documented in a logbook under the supervision of certifying staff

The module exams are administered by approved MTOs across Europe. You register directly with the training organisation, pay the exam fee, and schedule a session. Module certificates are issued after you pass each exam. The time limits are generally adequate for well-prepared candidates, but time management still matters. Some questions are straightforward recall of a regulation or definition; others are scenario-based, asking you to apply the requirements to a maintenance situation. Answer the questions you are confident about first, flag the rest, and return to them after the initial pass.

Key Topics Covered

Module 10 legislation knowledge draws from the subject areas defined in Part-66 Appendix I. Understanding the structure of these topics is essential for efficient study:

1. Regulation (EU) No 1321/2014 and Its Annexes

The foundational regulation for aircraft maintenance personnel licensing and continuing airworthiness. Know its structure: Part-M (continuing airworthiness, CAMO, airworthiness review), Part-145 (approved maintenance organisations, release to service), Part-66 (licensing of certifying staff), and the training organisation annex evolving under Regulation (EU) 2023/989. This is the most heavily tested regulatory area in Module 10.

2. Part-66 — The Aircraft Maintenance Licence

Part-66 is the rule that creates your licence. It defines the categories — A (line maintenance), B1.1 aeroplane turbine, B1.2 aeroplane piston, B1.3 helicopter turbine, B1.4 helicopter piston, B2 (avionics), B3 (non-pressurised piston helicopters) — the 17 modules of Appendix I, the experience requirements of 66.A.30 (for example 5 years for B1.1, B1.3 and B2, 4 years for B1.2, 2 years for A and B3, reduced with recognised training), the basic knowledge requirements, and the privileges and limitations of certifying staff, including signing the Certificate of Release to Service.

3. Part-M and CAMO — Continuing Airworthiness

Part-M tells you how continuing airworthiness is managed: the CAMO (continuing airworthiness management organisation) maintains the aircraft maintenance programme, tracks ADs and life-limited parts, and organises the airworthiness review, which ends with the airworthiness review certificate. It also defines the obligations of owners and operators and the standards for maintenance records.

4. Part-145 — Approved Maintenance Organisations

Part-145 governs approved maintenance organisations: their facility and personnel requirements, the privileges granted by the approval, the quality system, and the release to service of aircraft (CRS) and components (EASA Form 1). Most certifying engineers work inside a Part-145 organisation, so understanding its requirements is essential exam material.

5. Airworthiness Directives and Service Bulletins

Airworthiness Directives are legally enforceable rules issued when an unsafe condition exists in a product. Engineers must know how to check for applicable ADs, how compliance is accomplished and recorded, and the difference between an AD (mandatory) and a manufacturer Service Bulletin (voluntary unless incorporated into an AD or the approved maintenance programme).

6. Release to Service and Maintenance Records

Part-M.A.801 and Part-145.A.50 define who may release an aircraft to service and how: the Certificate of Release to Service signed by authorised certifying staff, with the work performed, the data used, and the organisation referenced. Component maintenance is documented with the EASA Form 1. Precise record-keeping is a legal requirement — and a favourite exam subject.

Pass Rates and What They Mean for You

EASA does not publish official pass rates for the individual module exams. Industry estimates and feedback from MTOs consistently put first-attempt pass rates for the foundation modules (M1, M2, M9) in the 70–85% range, with the larger technical modules (M7, M11, M13, M15) and Module 10 somewhat lower. The practical experience and assessments under 66.A.30 are where candidates are most likely to be retested — which is why legislative knowledge matters beyond the written exams.

The challenge with legislation is that the material is dense and precise — there is little room for approximation. Candidates who memorise regulation numbers without understanding application tend to struggle. The most successful candidates focus on the regulatory framework: why each annex exists, how the parts relate, and how they apply in everyday maintenance operations.

Proven Study Strategies

Based on feedback from successful Part-66 candidates and instructors, the most effective study approach for EASA legislation includes:

• Understand the regulation structure — Regulation (EU) No 1321/2014 is organised into annexes (Part-M, Part-145, Part-66) and subparts. Create a mental map of how they relate — this makes recall during the exam much easier than memorising isolated facts.
• Focus on Part-66 and the release-to-service rules — Licensing requirements, privileges, and CRS content account for a large share of Module 10 questions.
• Practise with timed mock exams — Simulating the real exam conditions builds both speed and confidence. Use Skylicence Europe's exam simulation mode to get comfortable with the pacing and question format.
• Use adaptive difficulty — Start with basic definition questions and progress to harder scenario-based questions as your knowledge improves.
• Study the Part-66 Appendix I syllabus directly — It contains the subject areas and depth levels for every module. Use it as a checklist to ensure you have covered every topic that could appear.
• Read the actual regulation text — Regulation (EU) No 1321/2014 is freely available in EUR-Lex. Reading 66.A.30 or Part-M.A.801 in the original wording builds the precision you need for exam questions and real-world compliance.

Common Mistakes to Avoid

• Memorising without understanding — The exams test application of regulations to real-world situations, not rote recall of article numbers. Understand what each requirement means and how to apply it.
• Confusing related requirements — The CRS (Part-M.A.801 / Part-145.A.50) vs the EASA Form 1 (components) vs the airworthiness review certificate (Part-M) are easy to mix up. Build clear distinctions.
• Ignoring recent changes — The EU regulatory framework is amended regularly, most recently by Regulation (EU) 2023/989. Ensure your study materials reflect the current rule text — outdated information leads to wrong answers.
• Not reading the full question — A single word like "shall" vs "may" can completely change the correct answer. Read every question twice before selecting.
• Overlooking scenario questions — Some questions describe a maintenance scenario and ask for the correct regulatory response. These require synthesising knowledge from multiple annexes. Practise with scenario-based questions to prepare.

How EASA Legislation Fits Into Your Part-66 Journey

Legislation is one of the core subjects of the Part-66 licence, but it is far more than an exam topic. As a certifying engineer, you will use the framework daily — to decide whether a repair needs approved design data, whether an EASA Form 1 is valid, or whether you can sign a Certificate of Release to Service. Part-66 defines the privileges you hold and the limits of those privileges. Part-M and Part-145 tell you how continuing airworthiness is managed and what records must exist. Passing your Module 10 exam demonstrates to the competent authority that you can be trusted with the legal responsibility of releasing aircraft to service.

For a complete overview of the entire licensing process — including the module exams, experience requirements, and practical assessments — read our complete guide to becoming a Part-66 engineer. And to understand how the B1 and B2 categories affect your preparation strategy, see our B1 vs B2 category comparison.

Using AI to Accelerate Your Part-66 Exam Preparation

Modern AI-powered study platforms have transformed how engineers prepare for the EASA module exams. Tools like Skylicence Europe use adaptive learning algorithms that identify your weak areas and generate targeted practice questions. Instead of studying every regulation from cover to cover, the AI focuses your time on the specific topics where you need the most improvement.

The AI also provides instant, detailed feedback on every practice question — not just whether you got it right, but why the correct answer is correct and why each wrong option is wrong. This real-time feedback accelerates learning dramatically compared to traditional methods where you might have to flip through a textbook to find an explanation.

How Skylicence Europe Prepares You for the Part-66 Module Exams

Skylicence Europe offers 4,464 practice questions across all 17 modules, aligned to the Part-66 Appendix I syllabuses. Our AI-powered platform adapts question difficulty to your performance, provides detailed explanations for each answer, and tracks your progress across every module and subject area. The platform covers all the key subject areas — from aviation legislation to airframe systems to turbine engine theory — and generates both basic recall questions and complex scenario-based questions that simulate the real exam experience.

Start your Part-66 exam preparation with Skylicence Europe →

For a comprehensive deep dive into the legislation module — including section-by-section breakdowns of Regulation (EU) No 1321/2014 and sample scenario-based questions — read our Module 10 Deep Dive.