EASA Airworthiness Directives Explained: Reading an AD and Recording Compliance

A new AD for three aircraft

Monday's first job on ExampleCAMO's planning desk is a new airworthiness directive against the ExampleJet 100: cracks in a main landing gear fitting, an inspection within 600 flight cycles or 6 months, whichever occurs first, repeats after that, and a modification that ends the repeats. ExampleCAMO manages three ExampleJet 100s for ExampleAir. By tonight someone has to say which of them the AD hits, by when, and what goes into the record. (The directive, the aircraft and their numbers are invented for this guide.)

An airworthiness directive is, in the words of point 21.A.3B(a) of Part 21, "a document issued or adopted by the Agency which mandates actions to be performed on an aircraft or on a CMU to restore an acceptable level of safety, when evidence shows that the safety level of the aircraft, UAS or CMU may otherwise be compromised." The Agency is EASA. On the continuing airworthiness side, M.A.303 is one sentence: "Any applicable airworthiness directive must be carried out within the requirements of that airworthiness directive, unless otherwise specified by the Agency." The status of each AD then sits in the aircraft continuing airworthiness records under M.A.305(c).

Key facts

• An AD mandates actions on an aircraft or CMU "to restore an acceptable level of safety" (21.A.3B(a)).
• The Agency issues one when an unsafe condition exists and "is likely to exist or develop in other aircraft, UAS or CMUs" (21.A.3B(b)).
• Every AD names at least the unsafe condition, the affected aircraft or CMU, the action(s), the compliance time and the date of entry into force (21.A.3B(d)).
• M.A.303, and ML.A.303 for Part-ML aircraft, require an applicable AD to be carried out within its own requirements.
• AD status is part of the aircraft continuing airworthiness records (M.A.305(c)). For repeats, "only the last and next applications with the reference to the applicable parameter should be recorded in the current status" (AMC M.A.305(c)1).
• In EASA's FAQ, an AMOC is "an EASA approved deviation to an AD", and supersedure "always and automatically invalidates any AMOC related to that AD".

What an AD is, and who issues it

Point (c), left out here, has the design approval holder make "appropriate descriptive data and accomplishment instructions" available, which is why an AD usually cites the holder's service bulletin. Point (d) is the skeleton of every AD.

The AMC and GM to point (b) answer a question junior CAMO engineers ask: the aircraft met its certification basis, so how can it be unsafe?

The full AMC and GM are on the 21.A.3B rule page.

Who has to comply

Who answers for an aircraft's continuing airworthiness is set out in Continuing Airworthiness: Part-M and Part-CAMO. The tasks they answer for are M.A.301.

Item (4) is the AD's close relative, and the status record treats the two together. How the AD is carried out is M.A.303, and for Part-ML aircraft ML.A.303.

The AD sets its own timetable, unless the Agency specifies otherwise.

For the organisation doing the work, the AD is maintenance data. M.A.401 names it; 145.A.45 does not name ADs but points to M.A.401(b).

The rest of the Part-145 data rules are in Part-145 Maintenance Data and Performance.

Anatomy of an AD: an illustrative example

EASA-issued ADs are usually laid out under headings such as Applicability, Reason, Effective Date, Required Action(s) and Compliance Time(s), and Ref. Publications. The AD below is fictional, set out the same way so each part can be read against 21.A.3B(d).

Applicability first, in two layers: the type, then serial numbers and configuration. ExampleCAMO's third aircraft, XX-EXC (MSN-EXAMPLE-022), left the factory with EXAMPLE-MOD-7, so the AD does not apply to it, and the record says why. Then the reason, which tells the inspector what to look for. Then each required action on its own. Paragraph (5) is the one people miss, because it binds aircraft that do not carry the part today. EASA's FAQ 19493: "When an unsafe condition affects a certain Part Number, the AD applies to all aircraft for which installation of the part is eligible." And FAQ 19492, on confirming a part number from the records instead of on the aircraft: "Identification of a part by checking the aircraft records is only allowed if this is explicitly indicated in the AD requirements."

EASA's FAQ answers are not rule text, and EASA says so: "any information included in these FAQs shall only be considered as EASA's understanding on a specific matter, and cannot be considered in any way as legally binding."

Reading compliance times: "whichever occurs first", repeats and terminating action

"Whichever occurs first" sets two limits, and the action is due when the aircraft reaches either. Each runs on its own counter: cycles against the cycle total, months against the calendar. A utilisation forecast helps book the hangar slot. It does not belong in the limit. Record both numbers.

Paragraph (1) for ExampleCAMO's two affected aircraft, at the review on 1 June 2026:

XX-EXA flies about 160 cycles a month, so its cycle limit arrives in about three weeks. XX-EXB flies about 40 a month, so the calendar governs. Same AD, different governing limit, which is why the record carries both.

In this AD, repeats run from the last inspection. ExampleMRO inspects XX-EXA and finds no crack. The CRS is issued on 18 June 2026 at 19,010 FC. Under paragraph (2), the next inspection is due at 20,210 FC or on 18 June 2028, whichever occurs first.

The CRS date is the one that counts. EASA's FAQ 19496: "For any maintenance task, including AD required actions, the date of release is the date when the Certificate of Release to Service (CRS) is signed by duly authorised certifying staff." For tasks "with repetitive action having a calendar limit", the same FAQ asks the owner or CAMO to coordinate "the issuance of a release specifically and without undue delay".

In this AD, terminating action ends the paragraphs it names, not the AD. At its August check, ExampleMRO embodies SB EXAMPLE-32-002 on XX-EXB. The CRS is issued on 20 August 2026 at 17,125 FC, inside both limits. Paragraph (4) ends (1) and (2) for that aircraft. Paragraph (5) still applies, so an uninspected spare fitting from stores cannot go on.

When the AD changes: corrected, revised or superseded

EASA's AD FAQ separates three kinds of change. The middle column quotes it. The right-hand column is ExampleCAMO practice.

Proposed ADs, emergency ADs and State of Design ADs

Under Article 77 of the Basic Regulation, EASA is to "carry out on behalf of Member States the functions and tasks of the state of design, manufacture or registry" when those relate to design certification and mandatory continuing airworthiness information. Point (h) covers the designs EASA has certified:

Proposed ADs (PADs). EASA's FAQ 19415 says published PADs "remain open for consultation and comments prior to publication as an (eventual) AD", and "AMOC applications to PADs are not accepted." If the period ends on 15 December, FAQ 19489 allows comments "at any time up until 23:59 on 15 December." ExampleCAMO logs a PAD on its watch list and opens status entries only once the AD is issued.

Emergency ADs. Per FAQ 117167, for aircraft registered in an EASA Member State an FAA Emergency AD (EAD) adopted by EASA is "valid for compliance from the time of EAD issuance", and "as soon as the EAD is adopted by EASA, each affected operator (Applicability as stated in the EAD) is expected to comply, within the specified compliance time after that adoption." The FAA's later Final Rule AD differs only in its effective date, since "the EAD becomes effective ‘upon receipt’, whereas the Final Rule AD has a ‘fixed’ calendar date", and "the AD number is the same", so a status record can keep one entry for both. EASA's own emergency ADs are not described in the texts quoted here; the AD itself states its date of entry into force, on ad.easa.europa.eu.

State of Design ADs. Where the State of Design is outside the EASA Member States, EASA adopts its ADs automatically under Executive Director Decision 2019/018/ED. Per FAQ 19480, such an AD "becomes valid in Europe upon the day that AD becomes effective, unless the Agency issues a different decision (e.g. deviating AD, or statement of non-adoption). This decision applies to all State of Design ADs, not only those issued by the FAA." The engines of one joint US–French manufacturer are the exception: "The FAA and EASA are joint State of Design authorities, both publish ADs, but do not adopt the other party’s ADs." (FAQ 47525). So screen the State of Design authority's ADs, and any EASA decision departing from one.

AMOCs and compliance time extensions

When the AD's own method does not suit an aircraft, the route is an AMOC. EASA's AMOC FAQ: "An Alternative Method of Compliance (AMOC) is an EASA approved deviation to an AD." And: "An AMOC must provide a level of safety equivalent to the level of safety to be restored by compliance with the original AD."

More time on its own is not an AMOC: "Requests for extension of compliance time without other alternative compliance methods or compensative factors are in general not eligible for an AMOC application." Nor does the Agency grant one-off extensions: "EASA does not approve AD compliance time extension requests for individual cases." For an aircraft registered in an EASA Member State, the FAQ points to that State's national aviation authority for a temporary exemption.

An AMOC is tied to one AD. "The supersedure of an AD always and automatically invalidates any AMOC related to that AD." A revision does not: "The AMOC is still valid, as a revision of an AD cannot introduce more stringent requirements." Record the AMOC reference as the method of compliance on the entry it covers, so a supersedure shows you which entries lost it.

What the AD status record should show

These are the AD lines of M.A.305. Retention periods are in LLP Back-to-Birth Records and Component Tracking (M.A.305); Part-ML aircraft have their own point, ML.A.305.

What "current status" contains is in AMC M.A.305(c)1, the most useful half-page on the subject.

As columns, with ExampleCAMO's three aircraft on 1 September 2026:

Add a remarks column for an AMOC reference, or a software part number where point (e) applies. For a CAMO, the status is also part of knowing the configuration, as AMC1 CAMO.A.315 says.

The airworthiness review reads this record (Airworthiness Reviews and the ARC); the CRS side is in Part-M: Release to Service and Records.

A monthly AD review routine

This is ExampleCAMO's practice, not a requirement. Your exposition procedure governs.

1. Fix the scope: every type, engine, propeller and installed appliance you manage, with serial numbers and modification status. Equipment ADs get missed when the list stops at the airframe.
2. Pull what changed since the last review: new ADs, revisions, corrections and supersedures from EASA's Safety Publications Tool at ad.easa.europa.eu, and any measures from your competent authority.
3. Screen applicability per aircraft and component. Record "not applicable" with its reason, and any records check you relied on.
4. Work out every limit against current counters. Flag anything whose earliest limit falls before the next review plus your planning lead time.
5. Order the work precisely: AD number, revision, paragraph and service bulletin revision. For calendar-limited repeats, ask for the CRS without delay.
6. Refuse the MEL shortcut. EASA's FAQ: "As a general rule: unless clearly stated in the AD, it is not allowed to postpone the action required by the AD using the instructions of a DAH CDL or MMEL item, as applicable."
7. Close out and date it. When a CRS arrives, update the entry with its date, the totals, the method of compliance and the part done, and check it was entered within the 30 days in M.A.305(a). Date the review, because the AMC asks for "the date on which the status was updated."

Reading the directive in Avioverse

Step 3 is where the hours go. In the Avioverse workspace, ADs and SIBs under Reference open the Airworthiness Directives and Safety Information Bulletins libraries. Search takes a subject, an AD number, a TC holder or words from the page text. Filters narrow by class, status, Issued by, TC holder, model, ATA chapter and period, and Current or All decides whether superseded directives show. The filters sit in the page address, so a view can be bookmarked or shared.

Open an AD and the PDF sits beside a chat for that document, with the starters Summarise required actions, Affected applicability and Draft a compliance assessment. Use them for a first pass through a long applicability section or a multi-part required action, then check every line against the PDF. The applicability decision and the assessment stay yours. The Revisions:, Supersedes: and Superseded by: line links the other issues, so you can check you are reading the one in force.

The short Summary shown above an AD's PDF is written by AI. Treat it as a reading aid, not the directive. The AD text governs.

Know the limits. The library is a stored copy of published documents, so confirm an AD's current status on EASA's tool before you act. It does not match directives to your fleet, serial numbers or part numbers, and it keeps no compliance status, due dates or CRS entries. The AD status record stays in your continuing airworthiness record system. For a working list of the ADs you are following, a registry in Registries can hold AD number, revision, subject and your note. You keep it by hand, and it is your list, not the record.

Where to read it yourself

Every rule quoted here links to its rule page: the Part 21 points (Regulation (EU) No 748/2012) checked against the 2025-11-27 Easy Access Rules for Initial Airworthiness, the Part-M, Part-ML, Part-145 and Part-CAMO points (Regulation (EU) No 1321/2014) against the 2025-09-02 Easy Access Rules for Continuing Airworthiness, and Article 77 of the Basic Regulation (Regulation (EU) 2018/1139) against the 2023-01-16 Easy Access Rules for the Basic Regulation. The FAQ answers are from EASA's AD and AMOC FAQ pages, checked on 25 September 2026. They change without a revision number, so reread one before relying on it.