AD specific queries

EASA does not approve AD compliance time extension requests for individual cases.

For an aircraft registered in an EASA Member State, the National Aviation Authority of the Member State can grant individual (temporary) exemptions on AD compliance time in the event of unforeseen urgent operational circumstances or operational needs of a limited duration, in accordance with Basic Regulation, Article 71.

For any other aircraft, the State of Registry authority should be contacted.

An extension of the AD compliance time for an individual product without ‘compensating factors’ that would provide for an equivalent level of safety is not to be considered as Alternative Method of Compliance (AMOC) to an AD. See also AMOC FAQ.

When an unsafe condition affects a certain Part Number, the AD applies to all aircraft for which installation of the part is eligible. The reason for this is that the unsafe part could be installed on any of those aircraft at a later stage after issuance of the AD. The AD would contain a prohibition to install, or specify the conditions under which installation would be allowed, which are requirements that must also apply to aircraft that do not, on the effective date of the AD, have the part installed.

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. Only certifying staff is competent to make the final airworthiness determination and therefore the CRS reference date does not necessarily coincide with the date when the individual maintenance task was actually performed and signed off by maintenance staff.

In the EASA system, the owner/CAMO is not required to keep the (so called) dirty finger prints, i.e. the exact time of the performance of the maintenance (e.g. AD action) work card. However, the owner/CAMO must consider the specific cases of tasks with repetitive action having a calendar limit, where a significant lag could occur between the date of task performance and the date of the CRS (which “legally speaking” determines the effective date of accomplishment). In such cases, the owner/CAMO must coordinate with the maintenance organisation the issuance of a release specifically and without undue delay to cover the particular task that is subject to a calendar limit when it has been applied, to avoid any distortion regarding limits associated with such repetitive actions or, as an alternative, record the date of AD accomplishment in the CRS.

In determining if a lag between the date of task performance and the date of the CRS is “significant”, engineering judgment and common sense must be used. The following questions should be considered:

• how long is the time lag between the ‘due date' (calendar time limit required for the next AD action) and the actual date of (planned) accomplishment? For example,  2 days are significant for a monthly interval task, and obviously insignificant for a 5-year interval task);
• what is the technical content (e.g., inspection for corrosion) of the AD task?; where (e.g., inside hangar, or outside, salty or otherwise erosive/corrosive environment) will the aircraft be parked after AD action completion?;
• other factors may also be considered, affecting that single aircraft and/or operator etc.

It is also to be noted that AD compliance verification (enforcement) is not an EASA responsibility, but that of the National Aviation Authority of the State of Registry of the aircraft, and it is always recommended, if in doubt, to seek their advice.

When the Design Approval Holder can provide justification that the unsafe condition no longer exists, e.g. because all the affected parts have been removed from aircraft and are confirmed to have been taken out of circulation. In such a case, a Proposal for AD Cancellation would normally be published first to invite comments. Upon Cancellation, the AD (watermarked “CANCELLED”) remains in the AD Publishing Tool, an AD Cancellation Notice explains why the AD was cancelled and its requirements are deleted.

The official EASA position regarding ‘required’ application of SB instructions is as follows:

Through the DOA (Design Organisation Approval) oversight process, the Agency promotes that TC/STC holders designate a Service Bulletin (SB) as mandatory only if it is known to them that this SB will also be covered by an AD. In all other cases, the TC/STC holder should use a term like ’highly recommended‘ (or equivalent). However, this is not yet common practice and there are still cases where an SB is termed ’mandatory‘ by the TC/STC holder, although no AD is to be issued. The Agency has no legal tools to prohibit the use of the word ‘mandatory’ by TC/STC holders, but EASA Certification Memorandum CM-21.A-J-001 has been issued to provide advice and guidance on this subject.

The case of an SB for which an AD has been issued, irrespective of whether it is designated by the TC/STC holder as ‘mandatory’, ‘alert’ or ‘highly recommended’, is clear: these are part of the Mandatory Continuing Airworthiness Instructions and must be applied in all cases.

The case of SBs designated as ‘mandatory’, ‘alert’ or ‘highly recommended’ by the TC/STC holder for which no AD has been issued is more complex and the following cases should be considered:

• The TC/STC holder subsequently includes such SB (e.g. repetitive inspection instructions) in the manufacturer maintenance programme (Maintenance Review Board Report (MRBR) or Manufacturer Recommended Programme) for the aircraft concerned. In this case, the SB under consideration will need to be included in the aircraft maintenance programme as defined in Commission Regulation (EU) No 1321/2014, M.A.302(d) and (g) (see also AMC M.A.302(d)) to ensure compliance with instructions for continuing airworthiness issued by the TC/STC holder.
• The TC/STC holder does not include such SB in the manufacturer maintenance programme (MRBR or Manufacturer Recommended Programme) for the aircraft concerned. In this case, the final decision to apply such SB lies with the owner/operator or contracted CAMO, as M.A.302(g) does not apply.
• The TC/STC holder issues an SB defining a modification, the related embodiment instruction and the relevant scheduled maintenance requirements, where these may or may not be subsequently included in the manufacturer maintenance programme (MRBR or Manufacturer Recommended Programme) for the aircraft concerned. In case the SB will not be included in the manufacturer maintenance programme, the final decision to apply it or not lies with the owner/ operator or contracted CAMO. If the final decision is to apply the SB, then the aircraft maintenance programme needs to be updated to include the scheduled maintenance requirements.

Finally, in relation to points 2. and 3. above, for all non-mandatory modifications and/or inspections, including SBs classified by the TC/STC holder as ‘mandatory’, ‘alert’ or ‘highly recommended’ and not covered by a corresponding AD, for all large aircraft, or aircraft used in commercial air transport, an embodiment policy is to be established, as required by M.A.301(7.). That policy should then result in a substantiated (and recorded) operator’s decision for each SB to apply it, or not.

After an AD has been published, there may be the need to update its content. Depending on the impact of the changes that will be included, an AD can be corrected, revised or superseded.

An AD is corrected to incorporate a non-substantive change to an AD, which does not affect compliance with the AD, e.g. a typographical error.

A corrected AD retains its AD number (including its revision status). The effective date of a corrected AD does not change.

Consequently, when in compliance with a not-corrected AD, an aircraft is automatically in compliance with the corrected one.

If the consultation period stated in a PAD ends (e.g.) on 15 December, interested parties would be able to comment on the relevant PAD at any time up until 23:59 on 15 December.

Since October 2016, a new format to improve the taxonomy for ADs applicable to parts and appliances (equipment) has been fully implemented in the EASA Safety Publication Tool. The new settings enable users to find all ADs applicable to a particular category of parts and appliances, or find all ‘equipment’ ADs with a single search action, rather than (as was previously the case) having to select each ETSO approval holder separately.

Users can go to the Safety Publications Tool, advanced search and select APPLIANCES to start using the new taxonomy for equipment ADs.

Users can also define/amend their filter setting(s) accordingly, thereby ensuring to be notified when EASA publishes an AD or PAD that does not directly apply to aircraft, engine, or propeller type designs.

It is possible to either select ‘APPLIANCES’, or choose notification for (e.g.) ATA 25 EQUIPMENT / FURNISHINGS only, or even more detailed, (e.g. if the user does maintenance on seats only) selecting Cabin Crew Seats, Flight Crew Seats and Passengers Seats.

We have removed the company names of ETSO approval holders from the SP Tool taxonomy, except where a company also holds an STC approval that is the subject of an AD. For all existing ‘equipment’ ADs, we have specified the name of each approval holder (as it was at the time of AD issuance) in the subject line of the AD record. We will do the same for all future equipment ADs.

Identification of a part by checking the aircraft records is only allowed if this is explicitly indicated in the AD requirements.
For example: A review of aircraft delivery or maintenance records is acceptable in lieu of the inspection as required by this paragraph, provided those records can be relied upon for that purpose, and the Part Number and serial number can be conclusively identified from that review.

After an AD has been published, there may be the need to update its content. Depending on the impact of the changes that will be included, an AD can be corrected, revised or superseded.

An AD is revised to incorporate changes that make the AD requirements less stringent than the previous revision. This may occur, for example, when the applicability is reduced; when the compliance time is extended; when an optional alternative method of compliance is added; when an optional terminating action is added; when clarification is provided  (including correction of errors in the previous AD that made the accomplishment of that AD impossible); when non-substantive changes are incorporated (such as the change in the address where a Service Bulletin is available or a change in the name of the contact person)

A revised AD retains its AD number with the addition of the revision number, e.g., 2006-0067R1

Consequently, when in compliance with a previous revision of an AD, an aircraft is automatically in compliance with the new revision.

Anyway, if the AD requires a repetitive inspection, after the effective date of the new revision, compliance with the AD at the latest revision must be recorded.

The fact that none of the s/n listed in the Foreign AD are, at the time of adoption, registered in Europe, is not strictly relevant for the Foreign AD adoption process/decision. Any s/n aircraft could be registered in future, provided the aircraft complies with the EU-validated design specifications. If already adopted, this AD would then automatically be added to the ‘package’ of actions that must be accomplished on that product.

After an AD has been published, there may be the need to update its content. Depending on the impact of the changes that will be included, an AD can be corrected, revised or superseded.

An AD is superseded if accomplishment of that AD can no longer assure an adequate level of safety, of a single aircraft and/or of the fleet: this may occur, for example, if a more stringent requirement is added (compliance time and / or required action), or if the applicability is expanded to aircraft models and/or serial numbers not included in the original applicability.

This may also occur if an error is identified in the original AD, while it is physically possible to comply with that AD as published.

Consequently, even in compliance with the original (superseded) AD, the owner and/or the operator of an affected aircraft must always comply with the superseding AD.

A superseding AD has a new AD number.

The ALS is part of the certificated product (aircraft, engine, propeller) type design (Part 21.A.31.a), that contains the mandatory scheduled maintenance items and the limitations for part replacement, necessary to maintain compliance with that type design. For each individual aircraft, an approved aircraft maintenance programme (AMP) must be created, initially containing the ALS at the revision level applicable at the time of the aircraft’s first certificate of airworthiness.

The ALS content is regulated by the airworthiness codes, e.g. CS 25.1529, Appendix H25.4. Each subsequent change to the ALS is approved by EASA. In view of the nature of the tasks contained in the ALS, failure to comply with an ALS revision (i.e. new or more restrictive tasks) would – in general – lead to an unsafe condition. Since EASA (under art. 77(1) of regulation (EU) 2018/1139) carries out the ICAO functions and tasks of the State of Design on behalf of EASA Member States, EASA notifies new or more restrictive ALS tasks as ‘Mandatory Continued Airworthiness Information’ to ICAO Contracting States by taking AD action for these specific ALS revisions.

In case an ALS revision only provides ‘relief’ (less restrictive), no AD will be issued, as there would be no ‘safety’ justification for such action. The existing EASA AD for a previous ALS revision, however, always allows the use of ‘later approved revisions’ to ensure compliance with the AD, which includes the use of any extended compliance time(s).

Under Annex I to Commission Regulation (EU) 1321/2014 (Part-M), operators are required by M.A.302 (a) to have an approved AMP, which establishes compliance –  M.A.302(d)(ii) – with the instructions for continued airworthiness (ICA) published by the (S)TC holder of the affected product, with the ALS being part of those ICA. However, Part-M does not specify exactly when, after publication of an ALS revision, an AMP must demonstrate compliance with that particular ALS revision and, consequently, from which time the new or more restrictive ALS tasks must be complied with. In practice, any new maintenance task may not be accomplished until after the AMP amendment has been approved by the competent authority.

These are additional reasons why EASA issues an AD for an ALS revision: to require, from the effective date of the AD (even before the AMP amendment), the accomplishment of the maintenance tasks (before exceeding their due date) and to require the amendment of the AMP within a clear (and reasonable) compliance time.

For affected aircraft registered in an EASA Member State, the requirements of an FAA Emergency AD (EAD) adopted by EASA are valid for compliance from the time of EAD issuance, which means that, 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 EASA Member States’ NAAs (who receive a copy of the EAD directly from the FAA) are expected to notify the operators and thereafter verify compliance (enforcement).

After some time the FAA will also issue a Final Rule AD. It should be noted that the only real difference between EAD and Final Rule AD is the effective date: the EAD becomes effective ‘upon receipt’, whereas the Final Rule AD has a ‘fixed’ calendar date. The technical requirements and the compliance time are identical in both documents. Therefore, EASA removes and replaces the EAD with the Final Rule AD in the EASA Safety Publications Tool.

To clarify the above, for each next case when a Final AD for an existing EAD is issued, the record for the EAD in the EASA SP Tool is updated by inserting the text "This AD is effective Month xx, YYYY to all persons except those persons to whom it was made immediately effective by FAA Emergency AD YYYY-XX-XX, issued on Month XX, YYYY, which was adopted by EASA and contained the requirements of this AD” into the field ‘Remarks’" of the EASA SP Tool AD record. However, the effective date of the AD record in the SP Tool will remain that of the EAD.

In addition, we insert (for reference purposes only) the full URL of the FAA EAD, as it remains in the FAA database, into the field ‘Remarks’ of the EASA SP Tool AD record. Please note that this will be done for future cases only. EASA does not plan to retrospectively update other existing records for FAA ADs that started life as Emergency AD.

Finally, it should be noted that recording of the AD (when complying) is not an issue: the AD number is the same, which means that when an aircraft has complied with the EAD it is also compliant with Final Rule AD. Consequently, once the EAD has been complied with, no (additional) compliance demonstration is necessary for the Final Rule AD when that is issued.