What is EASA Part-66?
EASA Part-66 is the regulatory standard that defines the knowledge, experience, and examination requirements for issuing an Aircraft Maintenance Engineer licence within the European Aviation Safety System. It is published as Commission Regulation (EU) No 1321/2014 — Annex III — and is legally binding across all EASA member states. The regulation sets out exactly which knowledge modules must be passed, what level of understanding is required for each subject, and how much practical maintenance experience a candidate must accumulate before a licence can be issued.
The purpose of the licence is to allow the holder to issue a Certificate of Release to Service (CRS) — the document that legally certifies an aircraft as airworthy and fit for flight after maintenance has been carried out. Without a valid Part-66 licence and appropriate type rating, no engineer can legally sign off an aircraft in an EASA-regulated environment.
Licence Categories Explained
EASA Part-66 defines three main licence categories, each with different scope and module requirements:
Category A — Certifying Mechanic
Category A allows the holder to issue a CRS for minor scheduled line maintenance and simple defect rectification within the limitations of the maintenance data. It is the entry-level licence and requires fewer modules than B categories. A Category A licence must be exercised within the scope of an approved Part-145 maintenance organisation.
Category B1 — Mechanical Systems
Category B1 covers maintenance and certification of mechanical systems and structures on aircraft, including turbine-powered aeroplanes and helicopters. B1 engineers are authorised to issue a CRS for the full range of airframe and engine maintenance tasks within their endorsed aircraft type. This is the most common licence category for commercial aviation maintenance work.
Category B2 — Avionics and Electrical
Category B2 covers avionics and electrical systems. B2 engineers certify work on aircraft communication, navigation, and flight management systems. With the increasing sophistication of modern aircraft electronics, demand for qualified B2 engineers has grown substantially over the past decade.
Knowledge Module Requirements
To obtain an EASA Part-66 licence, candidates must pass written examinations covering the required knowledge modules for their licence category. The modules and the minimum pass mark (75%) are set out in AMC1 Appendix II of the regulation:
| Module | Subject | B1 | B2 |
|---|---|---|---|
| 1 | Mathematics | ✅ | ✅ |
| 2 | Physics | ✅ | ✅ |
| 3 | Electrical Fundamentals | ✅ | ✅ |
| 4 | Electronic Fundamentals | ✅ | ✅ |
| 5 | Digital Techniques / Avionics | ✅ | ✅ |
| 6 | Materials and Hardware | ✅ | ✅ |
| 7 | Maintenance Practices | ✅ | ✅ |
| 8 | Basic Aerodynamics | ✅ | ✅ |
| 9 | Human Factors | ✅ | ✅ |
| 10 | Aviation Legislation | ✅ | ✅ |
| 11 | Aeroplane Aerodynamics, Structures & Systems | ✅ | — |
| 13 | Aircraft Aerodynamics, Structures & Systems | — | ✅ |
| 15 | Gas Turbine Engine | ✅ | — |
| 17 | Propeller | ✅ (if applicable) | — |
EASA Part-66 vs DGCA CAR-66: Key Differences
For Indian engineers, understanding the relationship between EASA Part-66 and DGCA CAR-66 is important for planning a career that may span both domestic and international environments.
- Jurisdiction: DGCA CAR-66 is valid in India; EASA Part-66 is valid across EU member states and bilaterally recognised countries.
- Module content: Modules 1–10 are nearly identical in both frameworks. Differences emerge primarily in Module 10 (jurisdiction-specific legislation) and the type-specific modules (11–17).
- Examination format: Both use MCQ-based computer examinations with a 75% pass threshold per module.
- Mutual recognition: India and the EU do not currently have a full bilateral aviation safety agreement for licence recognition. Indian engineers wishing to work in EASA jurisdictions must typically sit the relevant EASA module examinations separately.
- Experience requirements: Both frameworks require documented practical maintenance experience before the licence is issued — typically 3 years for B1/B2 under DGCA CAR-66.
💡 Practical insight: If you are preparing for DGCA CAR-66 and considering EASA Part-66 in the future, the good news is that your preparation overlaps by roughly 80%. Modules 1–9 are substantively the same in both frameworks. Investing in deep conceptual understanding now — rather than rote memorisation — will serve you well for both licences.
Experience Requirements and Licence Issue
Passing the knowledge modules is necessary but not sufficient for licence issue. Under EASA Part-66, candidates must also demonstrate a minimum period of practical aircraft maintenance experience. For Category B1 on turbine-powered aeroplanes, this is typically 3 years of practical experience on operating aircraft. The experience must be documented and verifiable — logbooks, employment records, and certifying statements from supervisors are all commonly required.
Once the examination and experience requirements are met, the licence is applied for through the competent authority of the relevant EASA member state, or through DGCA in India's case. The licence itself carries no expiration date but authorisations to certify specific aircraft types (type ratings) must be kept current through continued involvement in relevant maintenance activity.
Preparing for EASA Part-66 with AlwaysAME
AlwaysAME's question banks are aligned to the EASA Part-66 / DGCA CAR-66 common syllabus, making them directly applicable to both examinations. The platform covers all 14 modules with original MCQs written against the official AMC1 Appendix II learning objectives. Candidates preparing for either framework will find the content directly relevant and exam-representative.
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