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Classification and installation (components)

M.A.501

M.A.501(a) Components classification

(a) All components shall be classified into the following categories:

(1) Components which are in a satisfactory condition, released on an EASA Form 1 or equivalent and marked in accordance with Subpart Q of Annex I (Part 21) to Regulation (EU) No 748/2012, unless otherwise specified in point 21.A.307 of Annex I (Part 21) to Regulation (EU) No 748/2012, or in this Annex (Part-M), or in Annex Vd (Part-CAO).

AMC M.A.501(a)(1) EASA Form 1 or equivalent

(a) A document equivalent to an EASA Form 1 may be:

(1) a release document issued by an organisation under the terms of a bilateral agreement signed by the European Union;


(2) a release document issued by an organisation approved under the terms of a JAA bilateral agreement until superseded by the corresponding agreement signed by the European Union;


(3) a JAA Form One issued prior to 28 November 2004 by a JAR 145 organisation approved by a JAA Full Member State;


(4) in the case of new aircraft components that were released from manufacturing prior to the Part 21 compliance date, the component should be accompanied by a JAA Form One issued by a JAR 21 organisation and approved by a JAA Full Member State within the JAA mutual recognition system;


(5) a JAA Form One issued prior to 28 September 2005 by a production organisation approved by a competent authority in accordance with its national regulations;


(6) a JAA Form One issued prior to 28 September 2008 by a maintenance organisation approved by a competent authority in accordance with its national regulations;


(7) a release document acceptable to a competent authority according to the provisions of a bilateral agreement between the competent authority and a third country until superseded by the corresponding agreement signed by the European Union. This provision is valid provided the above agreements between the competent authority and a third country are notified to the European Commission and to the other competent authorities in accordance with Article 68 of Regulation (EU) 2018/1139;


(8) a release document issued under the conditions described in Article 4 point 6 of Regulation (EU) No 1321/2014);


(9) a ‘declaration of maintenance accomplished’ issued by the person or organisation that performed the maintenance, as specified in point M.A.502(e).

(b) Any item in storage without an EASA Form 1 or equivalent cannot be installed on aircraft registered in a Member State unless an EASA Form 1 is issued for such item by an appropriately approved maintenance organisation in accordance with AMC M.A.613(a) or AMC1 CAO.A.070(a) or AMC2 145.A.50(d).

GM1 M.A.501(a)(1) Classification and installation

Point (b) of 21.A.307 specifies new components that do not need an EASA Form 1 or equivalent to be eligible for installation. Point (c) of 21.A.307 specifies the conditions for the document accompanying the component.

(2) Unserviceable components which shall be maintained in accordance with this Regulation.

GM1 M.A.502(a)(2) Unserviceable components

(a) The person or organisation that performs maintenance should ensure the proper identification of any unserviceable components. The unserviceable status of the component should be clearly declared on a tag together with the component identification data and any information that is useful to define actions that are necessary to be taken. Such information should state, as applicable, in-service times, maintenance status, preservation status, failures, defects or malfunctions reported or detected, exposure to adverse environmental conditions, and whether the component is installed on an aircraft that was involved in an accident or incident. Means should be provided to prevent unintentional separation of this tag from the component.

(b) Unserviceable components should typically undergo maintenance due to:


(1) expiry of the service life limit as defined in the aircraft maintenance programme;
(2) non-compliance with the applicable airworthiness directives and other continuing airworthiness requirements mandated by the Agency;
(3) absence of the necessary information to determine the airworthiness status or eligibility for installation;
(4) evidence of defects or malfunctions;
(5) being installed on an aircraft that was involved in an incident or accident likely to affect the component’s serviceability.

(3) Components categorised as unsalvageable because they have reached their mandatory life limitation or contain a non-repairable defect.

AMC1 M.A.501(a)(3) Unsalvageable components

The following types of components should typically be classified as unsalvageable:
(a) components with non-repairable defects, whether visible or not to the naked eye;
(b) components that do not meet design specifications, and cannot be brought into conformity with such specifications;

(c) components subjected to unacceptable modification or rework that is irreversible;
(d) life-limited parts that have reached or exceeded their mandatory life limitation, or have missing or incomplete records;
(e) components whose airworthy condition cannot be restored due to exposure to extreme forces, heat or adverse environmental conditions;
(f) components for which conformity with an applicable airworthiness directive cannot be accomplished;
(g) components for which maintenance records and/or traceability to the manufacturer cannot be retrieved.

(4) Standard parts used on an aircraft, engine, propeller or other aircraft component when specified in the maintenance data and accompanied by evidence of conformity traceable to the applicable standard.

AMC1 M.A.501(a)(4) Standard parts

(a) Standard parts are parts that are manufactured in complete compliance with an established industry, Agency, competent authority or other government specification which include design, manufacturing, test and acceptance criteria, and uniform identification requirements. The specification should include all the information that is necessary to produce and verify conformity of the part. It should be published so that any party may manufacture the part. Examples of such specifications are National Aerospace Standards (NAS), Army-Navy Aeronautical Standard (AN), Society of Automotive Engineers (SAE), SAE Sematec, Joint Electron Device Engineering Council, Joint Electron Tube Engineering Council, and American National Standards Institute (ANSI), EN Specifications, etc.

(b) To designate a part as a standard part, the TC holder may issue a standard parts manual accepted by the competent authority of the original TC holder or may make reference in the parts catalogue to the specification to be met by the standard part. Documentation that accompanies standard parts should clearly relate to the particular parts and contain a conformity statement plus both the manufacturing and supplier source. Some materials are subject to special conditions, such as storage conditions or life limitation, etc., and this should be included in the documentation and/or the material’s packaging.


(c) An EASA Form 1 or equivalent is not normally issued and, therefore, none should be expected.

AMC2 M.A.501(a)(4) Standard parts CS22

For sailplanes and powered sailplanes, non-required instruments and/or equipment that are certified under the provision of CS 22.1301(b), if those instruments or equipment, when installed, functioning, functioning improperly or not functioning at all, do not in themselves, or by their effect upon the sailplane and its operation, constitute a safety hazard.
‘Required’ in the term ‘non-required’, as used above, means required by the applicable airworthiness code (CS 22.1303, 22.1305 and 22.1307) or required by the relevant regulations for air operations and the applicable Rules of the Air or as required by air traffic management (e.g. a transponder in certain controlled airspace). Examples of non-required equipment which can be considered to be standard parts may be electrical variometers, bank/slip indicators ball-type, total energy probes, capacity bottles (for variometers), final glide calculators, navigation computers, data logger/barograph/turnpoint camera, bug-wipers and anti-collision systems. Equipment which must be approved in accordance with the airworthiness code shall comply with the applicable ETSO or equivalent and it is not considered to be a standard part (e.g. oxygen equipment).

(5) Material both raw and consumable used in the course of maintenance when the organisation is satisfied that the material meets the required specification and has appropriate traceability. All materials must be accompanied by documentation clearly relating to the particular material and containing a conformity to specification statement plus both the manufacturing and supplier source.

AMC M.A.501(a)(5) Material

(a) Consumable material is any material which is only used once, such as lubricants, cements, compounds, paints, chemical dyes and sealants, etc.

(b) Raw material is any material that requires further work to make it into a component part of the aircraft, such as metals, plastics, wood, fabric, etc.


(c) Material both raw and consumable should only be accepted when satisfied that it is to the required specification. To be satisfied, the material and/or its packaging should be marked with the applicable specification and, where appropriate, the batch number.


(d) Documentation that accompanies all materials should clearly relate to the particular material and contain a conformity statement plus both the manufacturing and supplier source. Some materials are subject to special conditions, such as storage conditions or life limitation, etc., and this should be included in the documentation and/or the material’s packaging.


(e) An EASA Form 1 or equivalent should not be issued for such materials and, therefore, none should be expected. The material specification is normally identified in the (S)TC holder’s data except in the case where the Agency or the competent authority has agreed otherwise.

M.A.501(b) Component condition

(b) Components, standard parts and material shall only be installed on an aircraft or a component when they are in a satisfactory condition, belong to one of the categories listed in point (a) and the applicable maintenance data specifies the particular component, standard part or material.

GM1 M.A.501(b) Incoming inspection

(a) To ensure that components, standard parts and materials are in satisfactory condition, the persons referred to under M.A.801(b)(1), M.A.801(b)(2) or M.A.801(c), or the approved maintenance organisation should perform an incoming physical inspection.

(b) The incoming physical inspection should be performed before the component is installed on the aircraft.


(c) The following list, although not exhaustive, contains typical checks to be performed:


(1) verify the general condition of the components and their packaging in relation to damages that could affect their integrity;
(2) verify that the shelf life of the component has not expired;
(3) verify that items are received in the appropriate package in respect of the type of the component: e.g. correct ATA 300 or electrostatic sensitive devices packaging, when necessary;
(4) verify that the component has all plugs and caps appropriately installed to prevent damage or internal contamination. Care should be taken when tape is used to cover electrical connections or fluid fittings/openings because adhesive residues can insulate electrical connections and contaminate hydraulic or fuel units.

(5) verify that the release certificate accompanying each new component satisfies the release requirements established in point 21.A.307 as applicable in relation to the particular product on which the component is being installed.

(d) Items (e.g. fasteners) purchased in batches should be supplied in a package. The packaging should state the applicable specification/standard, P/N, batch number, and the quantity of the items. The documentation that accompanies the material should contain the applicable specification/standard, P/N, batch number, supplied quantity, and the manufacturing sources. If the material is acquired from different batches, acceptance documentation for each batch should be provided.

GM2 M.A.501(b) Installation of components

Components, standard parts and materials should only be installed when they are specified in the applicable maintenance data as specified in M.A.401(b). So, a component, standard part and material can only be installed after having checked the applicable maintenance data. This check should ensure that the part number, modification status, limitations, etc., of the component, standard part or material are the ones specified in the applicable maintenance data of the particular aircraft or component where the component, standard part or material is going to be installed. When the installation is performed outside a maintenance organisation, that is by the persons referred to in M.A.801(b)(1), M.A.801(b)(2), or M.A.801(c), then these persons are responsible to perform this check before installation. When the installation is performed by a Part-M Subpart F organisation or an organisation approved in accordance with Part-CAO, then the organisation has to establish procedures to ensure that this check is performed before installation.

Updated on 16/06/2021

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