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Aircraft maintenance programme

M.A.302

M.A.302(a) Organisation of maintenance

(a) Maintenance of each aircraft shall be organised in accordance with an AMP.

GM M.A.302(a) AMP applicability

A maintenance programme may indicate that it applies to several aircraft registrations as long as the maintenance programme clearly identifies the effectivity of the tasks and procedures that are not applicable to all of the listed registrations.

M.A.302(b) AMP amendments

(b) The AMP and any subsequent amendments thereto shall be approved by the competent authority.

M.A.302(c) Indirect approval

(c) When the continuing airworthiness of aircraft is managed by a CAMO or CAO, or when there is a limited contract between the owner and a CAMO or CAO concluded in accordance with point M.A.201(i)(3), the AMP and its amendments may be approved through an indirect approval procedure.

In that case, the indirect approval procedure shall be established by the CAMO or CAO concerned as part of the continuing airworthiness management exposition (‘CAME’) referred to in point CAMO.A.300 of Annex Vc or point M.A.704 of this Annex, or as part of the combined airworthiness exposition (‘CAE’) referred to in point CAO.A.025 of Annex Vd and shall be approved by the competent authority responsible for that CAMO or CAO.

The indirect approval procedure shall only be used when the CAMO or CAO concerned is under the oversight of the Member State of registry of aircraft, unless a written contract has been concluded in accordance with point 3 of point M.1 transferring responsibility for the approval of the aircraft maintenance programme to the competent authority responsible for the CAMO or CAO.

M.A.302(d) AMP compliance

(d) The AMP shall demonstrate compliance with:

(1) the instructions issued by the competent authority;

(2) the instructions for continuing airworthiness:

(i) issued by the holders of the type certificate, restricted type certificate, supplemental type certificate, major repair design approval, ETSO authorisation or any other relevant approval issued under Annex I (Part-21) to Regulation (EU) No 748/2012;
(ii) included in the certification specifications referred to in point 21.A.90B or 21.A.431B of Annex I (Part-21) to Regulation (EU) No 748/2012, if applicable;

(3) the applicable provisions of Annex I (Part-26) to Regulation (EU) 2015/640.

AMC M.A.302(d) AMP basis and associated programmes

1. An aircraft maintenance programme should normally be based upon the maintenance review board (MRB) report where applicable, the maintenance planning document (MPD), the relevant chapters of the maintenance manual or any other maintenance data containing information on scheduling. Furthermore, an aircraft maintenance programme should also take into account any maintenance data containing information on scheduling for components.

2. Instructions issued by the competent authority can encompass all types of instructions from a specific task for a particular aircraft to complete recommended maintenance schedules for certain aircraft types that can be used by the owner/operator directly. These instructions may be issued by the competent authority in the following cases:
— in the absence of specific recommendations of the Type Certificate Holder.
— to provide alternate instructions to those described in the subparagraph 1 above, with the objective of providing flexibility to the operator.

3. Where an aircraft type has been subjected to the MRB report process, an operator should normally develop the initial aircraft maintenance programme based upon the MRB report.

4. Where an aircraft is maintained in accordance with an aircraft maintenance programme based upon the MRB report process, any associated programme for the continuous surveillance of the reliability, or health monitoring of the aircraft should be considered as part of the aircraft maintenance programme.

5. Aircraft maintenance programmes for aircraft types subjected to the MRB report process should contain identification cross reference to the MRB report tasks such that it is always possible to relate such tasks to the current approved aircraft maintenance programme. This does not prevent the approved aircraft maintenance programme from being developed in the light of service experience to beyond the MRB report recommendations but will show the relationship to such recommendations.

6. Some approved aircraft maintenance programmes, not developed from the MRB process, utilise reliability programmes. Such reliability programmes should be considered as a part of the approved maintenance programme.

7. Alternate and/or additional instructions to those defined in paragraphs M.A.302(d)(1) and (2), proposed by the owner or the operator, may include but are not limited to the following:
— Escalation of the interval for certain tasks based on reliability data or other supporting information. Appendix I to AMC M.A.302 and AMC M.B.301(b) recommends that the maintenance programme contains the corresponding escalation procedures. The escalation of these tasks is directly approved by the competent authority, except in the case of ALIs (Airworthiness Limitations), which are approved by the Agency.
— More restrictive intervals than those proposed by the TC holder as a result of the reliability data or because of a more stringent operational environment.
— Additional tasks at the discretion of the operator.

Can a competent authority require the owner/CAMO/CAO to include national requirements in the Aircraft Maintenance Programme (AMP), based on M.A.302(d)(1)?

Although the Member State’s competent authorities are responsible for approving the AMP, the intention of the rule is that they should not impose aeronautical instructions (such as national requirements) in addition to the instructions for continuing airworthiness (ICA) issued by the design approval holder during the certification process with the Agency. The Agency is, on behalf of the Member States, the competent authority for initial airworthiness as per Article 77(1) of Regulation (EU) 2018/1139 (the EASA ‘Basic Regulation’). Following M.A.302(d)(2), those ICA shall be the basis to develop an AMP.

Nevertheless, competent authorities may issue alternate instructions to ICA when such instructions aim to offer flexibility to the operator [AMC M.A.302(d) point (2)].

Additionally, the mentioned AMC facilitates the rare case, where there has been no ICA issued by the design approval holder for a particular aircraft, modification, repair or STC (Supplemental Type Certificate): competent authorities may issue relevant instructions for the AMP in this case.

Remarks:
- The airworthiness (initial and continuing) of the aircraft for which the Basic Regulation is not applicable, has to comply solely with the national rules of the state of registry; and
- There is no equivalent of US CFR Title 14 Part-43 Appendix E/Part-91 (§91.411) or Part-43 Appendix F/Part-91 (§91.413) in the EU system.

M.A.302(e) Deviations- Escalated intervals

(e) By derogation to point (d), the owner or the organisation managing the continuing airworthiness of the aircraft may deviate from the instruction referred to in point (d)(2) and propose escalated intervals in the AMP, based on data obtained from sufficient reviews carried out in accordance with point (h). Indirect approval is not permitted for the escalation of safety-related tasks. The owner or the organisation managing the continuing airworthiness of the aircraft may also propose additional instructions in the AMP.

How is it possible to escalate AMP task intervals?

General:
Some general expectations for escalation initiatives are described in the following paragraph:

a) It should be ensured that the AMP continues to be valid in light of the operating experience [M.A.302(h) – see FAQ n.47406].

b) It should form part of the analysis of the effectiveness of the AMP (if required by M.A.301(e)),

c) The AMP should include a procedure to manage the escalation of established intervals [AMC M.A.302 point (4) and point (2) of AMC M.B.301(c)].

Supported by a formal reliability programme if required by M.A.302(g) or voluntarily implemented [AMC M.A.302(d) point (6)] or collection and analysis of in-service experience.

 ‘Appendix I to AMC M.A.302 and AMC M.B.301(b)’ provides detailed guidelines for the integration of this information into the AMP.
d) If there is a CA(M)O involved, those points also have to be emphasised within the CA(M)E, as specified in Appendix V to AMC1 M.A.704, AMC1 CAMO.A.300 or AMC1 CAO.A.025.

Two different cases:
The escalation of AMP task intervals falls into the alternative instructions proposed by the owner/CA(M)O [M.A.302(e)] and distinguishes in the following cases:

Case 1:
Escalation of safety-related task intervals, which consist of all mandatory tasks (Airworthiness Limitation Section) as well as certain non-mandatory tasks issued by the DAH (Design Approval Holder) such as various MRBR (Maintenance Review Board Report) tasks [see note below], tasks related to emergency equipment, critical components.

Case 2:
Escalation of non-safety-related task (e.g. non-safety related MRBR task or a task recommended by a Service Letter) intervals
Note: In cases, where the aircraft type has been subjected to the MRB process, the following MRBR tasks should be considered safety-related:

- Failure Effect Category (FEC) ‘5’ (evident safety) and ‘8’ (hidden safety) tasks (systems and powerplant)
- SSI (Structural Significant Item) tasks
- L/HIRF (Lightning / High Intensity Radiated Field) tasks (as applicable)
- Stand-alone EWIS tasks (EZAP procedure)

Escalation approval:
The approval of a task escalations is addressed separately for each case:

Regarding case 1:
1.1 Escalation of mandatory tasks represents a change of the initial type design and therefore must be discussed and agreed between the DAH and the Agency*. 1.2 The AMP revision proposal and the information used to substantiate the escalation of non-mandatory tasks [AMC M.B.301(b)(6)] have to be evaluated by the competent authority [AMC M.B.301(b) point (2)]. Following a positive evaluation, a direct approval of the AMP revision will be issued by the competent authority, as stated in M.A.302(e).

Regarding case 2:
An indirect approval of the AMP through a CA(M)O is possible and described in more detail in FAQ n.19061.
* Exception may exist under certain condition for Two Star CMR (Certification Maintenance Requirement) (see AMC 25-19).   Remarks:
In all cases, task de-escalation may need to be considered based on the supporting data [AMC M.A.302(g) point (4)].
Escalation should not be confused with ‘permitted variations’ to AMP intervals, which applies to a unique aircraft for a unique occasion [‘Appendix I to AMC M.A.302 point (4)].

What kind of alternative (other than escalation) or additional instructions can be introduced in the AMP?

Examples of alternative/additional instructions to the Design Approval Holder’s (DAH) Instructions for Continuing Airworthiness (ICA) are listed below [see point (7) of AMC M.A.302(d):

1. De-escalation of task intervals (i.e. ‘more restrictive intervals’). Regardless of the source of the task, this may be eligible to indirect approval.

2. Additional scheduled maintenance tasks selected by the operator on voluntary basis (e.g. operator policy for interiors), or manufacturer recommendations outside ICA (e.g. Service Letter) linked to product improvements or maintenance practices... Depending on their nature, those tasks may be added, changed and deleted through the indirect approval [see FAQ n.19061].

Remark:
Additional and de-escalated tasks may originate from the reliability programme as indicated in point (4) of AMC M.A.302(g).

3. Concerning changes in task type (e.g. from General Visual Inspection to Detailed Inspection, or from Operational Check to Functional Check), by analogy with the escalation EASA recommends that for safety-related tasks such changes are directly approved by the competent authority. For non-safety related tasks, the competent authority may accept an indirect approval.

M.A.302(f) AMP contents

(f) The AMP shall contain details of all maintenance to be carried out, including frequency and any specific tasks linked to the type and specificity of operations.

M.A.302(g) Reliability programme

(g) For complex motor-powered aircraft, when the AMP is based on maintenance steering group logic or on condition monitoring, the AMP shall include a reliability programme.

AMC M.A.302(g) Reliability programmes

1. Reliability programmes should be developed for aircraft maintenance programmes based upon maintenance steering group (MSG) logic or those that include condition monitored components or that do not contain overhaul time periods for all significant system components.

2. Reliability programmes need not be developed for aircraft not considered complex motor-powered aircraft or that contain overhaul time periods for all significant aircraft system components.

3. The purpose of a reliability programme is to ensure that the aircraft maintenance programme tasks are effective and their periodicity is adequate.

4. The reliability programme may result in the escalation or deletion of a maintenance task, as well as the de-escalation or addition of a maintenance task.

5. A reliability programme provides an appropriate means of monitoring the effectiveness of the maintenance programme.

6. Appendix I to AMC M.A.302 and M.B.301(d) gives further guidance.

M.A.302(h) Periodic reviews

(h) The AMP shall be subject to periodic reviews and be amended accordingly when necessary. Those reviews shall ensure that the AMP continues to be up to date and valid in light of the operating experience and instructions from the competent authority, while taking into account new or modified maintenance instructions issued by the type certificate and supplemental type certificate holders and any other organisation that publishes such data in accordance with Annex I (Part-21) to Regulation (EU) No 748/2012.

AMC M.A.302 Basic principles

1. The term ‘maintenance programme’ is intended to include scheduled maintenance tasks the associated procedures and standard maintenance practises. The term ‘maintenance schedule’ is intended to embrace the scheduled maintenance tasks alone.

2. The aircraft should only be maintained to one approved maintenance programme at a given point in time. Where an owner or operator wishes to change from one approved programme to other, a transfer check or inspection may need to be performed in order to implement the change.

3. The maintenance programme details should be reviewed at least annually. As a minimum revisions of documents affecting the programme basis need to be considered by the owner or operator for inclusion in the maintenance programme during the annual review. Applicable mandatory requirements for compliance with Part-21 should be incorporated into the aircraft maintenance programme as soon as possible.

4. The aircraft maintenance programme should contain a preface which will define the maintenance programme contents, the inspection standards to be applied, permitted variations to task frequencies and, where applicable, any procedure to manage the evolution of established check or inspection intervals.

5. Repetitive maintenance tasks derived from modifications and repairs should be incorporated into the approved maintenance programme.

6. Appendix I to AMC M.A.302 and AMC M.B.301(b) provide detailed information on the contents of an approved aircraft maintenance programme.

When should I revise my Aircraft Maintenance Programme (AMP)?

In accordance with M.A.302(h), the Aircraft Maintenance Programme (AMP) shall be subject to ‘periodic reviews’ and amended accordingly when necessary. 

This means that the owner/operator/CA(M)O should review at a regular interval:

- new/modified maintenance instructions by the TC holder, 
- modifications and repairs embodied in the particular a/c, which may require compliance to additional maintenance instructions (by Design Approval Holder),
- in-service experience collected for the particular a/c or for the fleet and
- changes in the type and specificity of operations.

Such a review allows to determine if an AMP revision is necessary to still comply with the obligations of M.A.302(h), and ensure that the AMP continues to be valid in light of the operating experience. As a minimum, point (3) of AMC M.A.302 states it should be at least annually.

However, this should not prevent amending the AMP outside of this formal periodic review, when a specific need arises. This may depend for example on in-service experience (e.g. adverse trend), nature of instruction revisions (e.g. significant reduction of TBO (time between overhaul)), the extent of instruction revisions (amount of affected tasks) as well as source of instruction revisions (e.g. MRBR, ALS, etc.)    

When a revision of the ALS (Airworthiness Limitation Section) introduces a new or more restrictive task, EASA has the policy to issue an AD (Airworthiness Directive). Such an AD would typically mandate on one side the revised task accomplishment and on the other side the revision of the AMP itself, together with a compliance time for these two actions.

However, in accordance with point (3) of AMC M.A.302, EASA recommends to review the AMP as soon as possible in this case to avoid a disconnection between accomplished maintenance task(s) and maintenance task(s) listed in the AMP.

If the aircraft’s continuing airworthiness is being managed by a CA(M)O, the CA(M)E (Continuing Airworthiness Management Exposition/Combined Airworthiness Exposition) should describe the AMP revision policy (including ‘periodic review’) under point 1.2 [Appendix V to AMC M.A.704], point 1.2 [AMC1 CAMO.A.300]  or point D.3 [AMC1 CAO.A.025].

Remark: In the case where the source documents are amended without having an effect on the AMP content, it is acceptable to use an indirect approval procedure (if granted by the competent authority in accordance with M.A.302(c)) to amend the relevant source document references in the AMP.
Updated on 23/06/2021

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