How to Read EASA Rules: IR, AMC, GM and CS

Why regulations read the way they do

Every aviation professional has had the experience: you open a regulation to answer one question and find yourself ten documents deep, unsure whether the paragraph in front of you is law, guidance, or somebody's slide deck. The confusion is not you — it is the structure. Aviation rules everywhere are layered: a small core of binding law, surrounded by progressively softer material that explains how to comply with it. Once you can tell the layers apart, you can read any of the world's rule systems, because they all descend from the same ICAO root and they all use some version of the same layering.

This guide teaches the reading skill on the EASA system — implementing rules, AMC, GM and certification specifications — and then maps it across the systems an EASA-trained professional most often meets: the FAA's 14 CFR, the UK CAA's post-Brexit mirror, the UAE GCAA, Saudi Arabia's GACA, and Transport Canada.

The EASA pyramid: one Basic Regulation, many implementing rules

At the top of the EU system sits Regulation (EU) 2018/1139 — the Basic Regulation — adopted by the European Parliament and the Council. It establishes EASA, sets the essential requirements, and empowers the European Commission to adopt the detailed rules. It replaced the previous framework: Article 139 states that "Regulation (EC) No 216/2008 is repealed with effect from 11 September 2018" — worth knowing, because you will still meet references to 216/2008 in older rule text, and Article 140 provides the transitional bridge that keeps certificates issued under the old framework valid under the corresponding provisions of the new one.

Below the Basic Regulation sit the implementing and delegated regulations the Commission adopts per domain — the rules you actually work with day to day: Regulation (EU) No 748/2012 for initial airworthiness, (EU) No 1321/2014 for continuing airworthiness, (EU) No 1178/2011 for aircrew, (EU) No 965/2012 for air operations. These are the hard law: binding in their entirety, published in the Official Journal of the European Union.

The third layer is issued not by the legislator but by the Agency itself. The Basic Regulation says so directly:

That one paragraph names the whole soft-law layer: certification specifications (CS), acceptable means of compliance (AMC) and guidance material (GM). Beyond it there is a fourth, informal layer — the FAQs and user guides EASA publishes on its website. Useful, often very good, but with no legal status at all: they are the Agency explaining itself, not the Agency ruling.

The document most professionals actually read is none of these in isolation but the Easy Access Rules — EASA's free consolidated publications that merge the officially published regulation with the related AMC, GM and CS into a single, continuously updated text. The Easy Access Rules are the working copy; the legally binding text remains the Official Journal version.

Anatomy of a rule reference

An implementing regulation has two parts. The cover regulation is a short set of articles — cited as "Article 3 of Regulation (EU) No 1321/2014" — handling scope, definitions and entry into force. The substance hangs off it as annexes, and each annex is a "Part". Regulation (EU) No 1321/2014 carries Annex I (Part-M), Annex II (Part-145), Annex III (Part-66), Annex IV (Part-147), Annex Va (Part-T), Annex Vb (Part-ML), Annex Vc (Part-CAMO) and Annex Vd (Part-CAO). Regulation (EU) No 965/2012 does the same for operations: a definitions annex, then Part-ARO, Part-ORO, Part-CAT, Part-SPA, Part-NCC, Part-NCO, Part-SPO and Part-IAM.

Rule identifiers encode their position. Take 145.A.30: "145" is the Part, "A" is the Section — Section A holds the requirements on the organisation, while Section B of the same Part holds the procedures for the competent authority overseeing it — and "30" is the rule. Newer Parts read even more directly: ORO.GEN.200 is Part-ORO, Subpart GEN (general requirements), rule 200. When soft law attaches to a rule, it borrows the rule's identifier with a prefix and counter: AMC1 145.A.120(b) is the first AMC to paragraph (b) of rule 145.A.120, and a GM1, GM2… series works the same way.

Two habits keep you out of trouble when reading consolidated text. First, check the applicability tags: a consolidated rule can carry two time-bound versions of the same clause side by side, each tagged with the date and regulation from which it applies — read the one in force today, not the first one printed. Second, expect references to repealed instruments: older rule text still cites Regulation (EC) No 216/2008 where today's reader should look to the corresponding provision of Regulation (EU) 2018/1139.

AMC and GM: what "acceptable" actually buys you

The definitions are precise, and the difference matters. An AMC is defined in EU rule text as "non-binding standards adopted by the Agency to illustrate means to establish compliance" with the Basic Regulation and its implementing rules. GM is softer still: "non-binding material developed by the Agency that helps to illustrate the meaning of a requirement or specification". An AMC shows you a way to comply; GM only helps you understand. Following an AMC earns you a presumption of compliance with the rule it supports. Following GM, by itself, demonstrates nothing.

Because AMC are non-binding, the system provides a formal escape hatch — the alternative means of compliance (AltMoC). Here is the Part-145 version:

And notice the register shift when the Agency's own AMC explains that rule — the binding "shall" of the implementing rule becomes the advisory "should" of soft law:

The fourth species of Agency soft law, certification specifications, lives mainly in the design world: CS-25 for large aeroplanes, CS-E for engines, and so on — the airworthiness codes against which a type is certified. They have their own guide in our Part-21 series.

The FAA system: one title of federal law

The United States writes its aviation rules as Title 14 of the Code of Federal Regulations — "14 CFR", still widely called the FARs — divided into numbered parts. There is no AMC/GM layer. The regulation is the regulation, and its opening section usually tells you exactly what it covers:

Two structural differences stand out to an EASA-trained reader. First, the airworthiness standards are inside the regulations: where EASA certifies a large aeroplane against CS-25 (Agency soft law), the FAA certifies against 14 CFR Part 25 — the design code is itself federal law. Second, the guidance layer is the Advisory Circular. ACs carry a standard disclaimer; AC 43-9D, on maintenance records, introduces itself as providing "one means, but not the only means, of ensuring that the contemplated maintenance, alterations, or continue-in-service condition is in compliance with applicable regulations and existing policy". That sounds like an AMC, but there is no formal presumption-of-compliance or AltMoC mechanism attached to it — you comply with the rule, and the AC is one recognised route. A further layer, FAA Orders such as Order 8900.1, instructs the FAA's own inspectors rather than the regulated public — the rough counterpart of EASA's Section B authority requirements.

Part numbers that rhyme: the EASA ↔ FAA crosswalk

The happiest accident for anyone working across the Atlantic is that many part numbers line up — not by accident at all, but because Europe's pre-EASA JARs were deliberately numbered to track the corresponding FAR parts, and EASA kept the numbers.

Mind the near-misses. The engineer's licence is Part-66 in Europe but Part 65 in the United States — there is no 14 CFR Part 66. And an identical number does not mean identical content: EASA Part-145 and 14 CFR Part 145 both govern maintenance organisations, but privileges, personnel requirements and release paperwork differ enough that bilateral agreements exist precisely to bridge them. The full comparison — licences, releases, and the bilateral itself — has its own guide in this series.

One ICAO root

Why do six different systems feel so similar? Because all of them implement the same treaty. The Chicago Convention of 1944 created ICAO, and ICAO maintains Standards and Recommended Practices (SARPs) across nineteen technical annexes — Annex 1 for personnel licensing, Annex 6 for aircraft operation, Annex 8 for airworthiness, and so on. Contracting states transpose the SARPs into national law and, under Article 38 of the Convention, must notify ICAO of any differences. A national regulation is, in essence, a state's answer sheet to the ICAO annexes — which is why the chapter headings rhyme even when the numbering does not.

The UK CAA: a mirror image, slowly diverging

The United Kingdom left the EASA system at the end of the Brexit transition period on 31 December 2020, but it did not write a new rulebook. The EU aviation regulations were carried into domestic law as retained (now "assimilated") law, so the UK flies under UK Regulation (EU) 2018/1139, UK Part-145, UK Part-M, UK Part-FCL — the same numbering, initially the same text, now amended independently by the UK. The CAA publishes its own consolidated versions of the UK regulations, plus its long-standing CAP series of Civil Aviation Publications and Official Record Series documents for the surrounding guidance. For a reader, the skill transfers one-for-one; the trap is currency. The two texts diverge amendment by amendment, so "I know the EASA rule" is no longer proof of the UK position — check the UK consolidation, not the EU one. The post-Brexit system has its own guide in this series.

GCAA, GACA and TCCA: three transplants

United Arab Emirates — GCAA

The UAE General Civil Aviation Authority writes Civil Aviation Regulations (CARs) that follow the EASA shape closely: CAR M, CAR 145, CAR 66 and CAR 147 mirror their EASA namesakes, and the advisory layer comes as Civil Aviation Advisory Publications (CAAPs). An EASA-trained engineer or CAMO professional can navigate the UAE system almost immediately — the reading skill is the same; the details differ.

Saudi Arabia — GACA

Saudi Arabia's General Authority of Civil Aviation went the other way. The GACA Regulations (GACARs) are drafted on the FAA model, with part numbers that track 14 CFR — GACAR Part 21, Part 43, Part 121, Part 145. If your next contract is in Jeddah, the reading skill you need is the FAA one: applicability sections, US-style defined terms, and no AMC layer.

Canada — TCCA

Transport Canada Civil Aviation maintains the Canadian Aviation Regulations — confusingly also "CARs" — and they are organised on neither the EASA nor the FAA template: subject-matter Parts numbered I through X, with maintenance in Part V (an approved maintenance organisation is an AMO under CAR 573) and personnel licensing, including aircraft maintenance engineers (AMEs), in Part IV. The distinctive feature is the parallel Standards layer: many CAR provisions are completed by an associated Standard, incorporated by reference, so reading a Canadian requirement usually means reading the regulation and its Standard together — closer in spirit to EASA's IR-plus-AMC pairing than anything in the FAA system. All three systems, and the ICAO root they answer to, are covered in depth in the final guide of this series.

Reading any regulation: the method

1. Identify the binding instrument and its current state. Which regulation, which amendment, in force today? Read from a current consolidation — Easy Access Rules, the eCFR, or the authority's own consolidated text.
2. Start at the applicability clause. Every part tells you who and what it captures — 145.1 above is a model of the genre. If it does not apply to you, stop reading.
3. Read the binding rule first — the "shall". Only then open the guidance that supports it, and keep the layers straight: AMC-type material carries compliance weight, GM-type material explains.
4. Check the date arithmetic. Applicability tags, transition periods and repealed cross-references are where confident readers go wrong.
5. Know which side of the fence a document sits on. Requirements on the organisation (EASA Section A) and instructions to the authority (Section B, FAA Orders) look similar and bind different people.

Where to read it yourself

Every EASA citation in this guide was checked against the Easy Access Rules revisions listed in the header — the Basic Regulation (2023-01-16 revision) and Continuing Airworthiness (2025-09-02 revision) — and the FAA text against the eCFR consolidation of 2026-05-18. The Easy Access Rules are free downloads from EASA; the eCFR is the US government's continuously updated consolidation; the UK CAA, GCAA, GACA and Transport Canada each publish their own current texts. For the EASA rules in daily use, our series on continuing airworthiness, Part-145, air operations and pilot licensing walk the individual Parts clause by clause.