Part 66 knowledge base
EASA Info
Plain-language answers to common Part-66 questions, sourced from EASA's own FAQs, so you know where exam prep fits into the bigger picture.
What are the Part-66 licence categories?
Part-66 licences are split into categories that define what maintenance work you're allowed to certify.
Category A
Minor scheduled maintenance and simple defect rectification. Split by aircraft type: A1 (turbine aeroplanes), A2 (piston aeroplanes), A3 (turbine helicopters), A4 (piston helicopters).
Category B1
Structure, powerplant, and mechanical/electrical systems, plus avionics work that only needs simple tests. Split the same way as Category A: B1.1–B1.4.
Category B2
Avionic and electrical systems, plus a limited set of minor line maintenance tasks.
Category B2L
Same scope as B2, but limited to specific system ratings: communication/navigation, instruments, auto-flight, surveillance, and airframe systems.
Category B3
Non-pressurised aeroplanes with a maximum take-off mass of 2,000 kg or less.
Category L
Sailplanes, balloons, and airships, with further subcategories (L1–L5) for composite/powered sailplanes and hot-air/gas balloons and airships.
Category C
Base maintenance on complex motor-powered aircraft and other aircraft types.
There are also base-maintenance support-staff categories tied to B1, B2, B2L, B3 and L, for people assisting on base checks without holding the full certifying licence.
Source: https://www.easa.europa.eu/en/the-agency/faqs/get-part-66-licence · Regulatory basis: 66.A.3 and 66.A.20, Annex III (Part-66) to Regulation (EU) No 1321/2014 · last checked against EASA on 2026-07-04.
How do I get a B1 or B2 licence?
Getting a B1 or B2 Aircraft Maintenance Licence (AML) happens in two phases.
Basic licence
Basic knowledge — the exams this site helps you prepare for — plus basic experience working on aircraft under supervision.
Aircraft type rating
Type training (theoretical and practical) plus on-the-job training (OJT) on that specific aircraft type.
Which exact path applies depends on the aircraft group (66.A.5) — "Group 1" aircraft and other aircraft types follow slightly different routes.
Licences from outside EASA member states aren't automatically converted or mutually recognised as an EASA Part-66 AML — confirm your route with the competent authority where you intend to apply.
Source: https://www.easa.europa.eu/en/faq/21067 · last checked against EASA on 2026-07-04.
What's the exam itself actually like?
The theoretical knowledge exams follow the same standard for every module, in every EASA member state.
75%
Pass mark
75% is the pass mark for every module — there's no partial credit and no separate curve per category.
3
Options per question
Multiple-choice, three options per question, only one correct answer. Time allowed works out to roughly 75 seconds per question.
0
Penalty for a wrong answer
A wrong answer costs you nothing beyond not being right, so it's always worth answering every question rather than leaving one blank.
Source: https://eur-lex.europa.eu/eli/reg/2014/1321/2026-02-22/eng · Regulatory basis: Appendix I to Part-66, Annex III to Regulation (EU) No 1321/2014 · last checked against EASA on 2026-07-04.
How much practical experience do I need?
Passing the exams is only half of a basic licence — you also need hands-on maintenance experience, and how much depends on your category and background.
Category A, B1.2, B1.4, B3
3 years of practical maintenance experience with no prior technical training, 2 years with relevant skilled-worker training, or 1 year after finishing an approved Part-147 basic training course.
Category B1.1, B1.3, B2
5 years with no prior technical training, 3 years with relevant skilled-worker training, or 2 years after an approved Part-147 basic training course.
At least 12 months of that experience (6 months for categories A and L) has to be in a Part-145 or Part-CAO approved organisation, and at least 1 year of it has to be recent — on the category of aircraft you're applying for.
Source: https://www.easa.europa.eu/en/the-agency/faqs/basic-part-66-licence-without-type-rating · Regulatory basis: 66.A.30 — Basic experience · last checked against EASA on 2026-07-04.
How does Part-66 relate to Part-145 and Part-147?
Part-66 doesn't work in isolation — it's one of three linked regulations that together cover the engineer, the workplace, and the training.
The engineer
Part-66
Licenses the individual engineer. Pass the exams, log the experience, and it lets you personally certify maintenance work (a Certificate of Release to Service).
The workplace
Part-145
Approves the maintenance organisation itself — the company you work for, not you personally.
The training
Part-147
Approves training organisations. Completing a full basic training course at an approved Part-147 school is what shortens the experience requirement.
Source: https://www.easa.europa.eu/en/the-agency/faqs/part-147 · Regulatory basis: Annex II (Part-145) and Annex IV (Part-147) to Regulation (EU) No 1321/2014 · last checked against EASA on 2026-07-04.
How do I apply for a licence?
Applications go through the competent authority of an EASA member state, not EASA itself.
First application
Fill in EASA Form 19 and submit it with evidence that you meet the requirements. Each authority sets its own fee and decides exactly how you demonstrate compliance.
Amendment or renewal
Apply to whichever member state issued your original licence, using the same Form 19 process.
Source: https://www.easa.europa.eu/en/the-agency/faqs/get-part-66-licence · Regulatory basis: 66.A.10, 66.A.15, 66.A.25, 66.A.30, 66.A.45, 66.A.70 and their AMC/GM · last checked against EASA on 2026-07-04.
Does this only apply inside the EU?
Part-66 is an EASA system, but its reach — and its influence on other countries' rules — goes wider than just the EU.
EASA member states
All EU countries, plus Norway, Iceland, Liechtenstein and Switzerland, operate under the same Part-66 licence.
Outside the EASA system
A licence issued outside EASA member states isn't automatically converted or recognised as an EASA Part-66 AML — you'd need to go through a conversion process with a competent authority.
Several authorities outside the EASA system — the UK CAA among them — run their own licence closely modelled on Part-66 (same modules, categories, and 75% pass mark), and a number of other countries' systems are influenced by it too. That's not the same as automatic recognition — always check equivalence with your own national authority before assuming your studying transfers directly.
Source: https://www.easa.europa.eu/en/faq/21067 · last checked against EASA on 2026-07-04.
This page summarises EASA guidance in our own words for convenience — regulations change, so if anything here looks out of date or you're about to make a decision based on it, verify with your national competent authority.
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