Additive Manufacturing

The purpose of this Certification Memorandum is to provide guidance regarding EASA certification effort expectations of industry associated with the introduction and use of Additive Manufacturing (AM) technologies (metallic and non-metallic) across a broad range of Products, Parts, and Appliances subject to showing compliance with CS-22, CS-VLA, CS-23, CS-25, CS-VLR, CS-27, CS-29, CS-E, CS-P, CS-APU, CS-ETSO, including other emerging product Certification Specifications (CSs) and Special Conditions (SCs), e.g. those
addressing VCA etc.

This CM has been developed in conjunction with tasks, priorities, and objectives identified in various industryregulator AM related activities, e.g. EAAMIRG Actions.

EAAMIRG Action Item 1: Part Classification and Authority Engagement
EAAMIRG Action Item 2: Standardisation: understanding and use of ‘standards’

Issue 3 of this CM was raised following rapid development in the planned use of AM since the initial release of the CM and also following considerable dialogue between industry and the regulators (in accordance with the intent of this CM at issue 1). Issue 3 included new guidance intended to support the existing certification specifications (see Appendix 1 of this CM ), some of which have been superseded by revision to AMC 25.603, 605, and 613, for CS25 at amdt.27 (intended to address materials, processes, and fabrication methods, including Advanced Manufacturing methods, such as AM). Issue 3 also included some guidance associated with the use of AM in non-critical applications and emphasised the importance of appropriate knowledge transfer and training.

Issue 4 builds upon subsequent industry-regulator AM activities, including the annual industry – regulator AM Event 2021, 2022, 2023 and 2024 Working Group activities, and progress made in other various Working Groups, e.g. EAAMIRG, AIA, MMPDS, and other Standards Development Organisations (SDOs). Issue 4 content has also been developed in response to industry questions to EASA. Amendments include reference to standardisation of understanding and awareness of criticality and new emphasis upon the importance of
developing appropriate thorough design safety assessment processes, e.g. FHAs, FMECAs, etc., particularly for non-Type Certificate Holder (TCH) organisations repairing or altering baseline structures and systems. Issue 4 also develops the intent for initial demonstration of certification effort to be proportionate to novelty, criticality, and complexity, and provides further guidance regarding the use of AM in no or low-criticality applications, including the addition of a new Appendix 5 ‘Examples’.

At the time of this CM revision, AM has been used for new parts or parts produced for the purpose of ‘repair by replacement’. Therefore, the scope for this CM Policy revision (Section 3) is limited to new parts or ‘repair by replacement’ for parts of no and low criticality. Further revision to this CM will be required for repairs involving material build up on baseline structure damaged (and prepared) surfaces.

Note: This CM does not address established and approved methods which may demonstrate similarities with the evolving definitions of AM, e.g. repetitive weld build-up repair processes accepted prior to the issue of this CM.

Note: This CM does not attempt to catalogue the use of, or repeat detail from, the many evolving industry guidance documents related to AM materials, processes, fabrication methods, or applications. The use of such guidance, e.g. as developed by standardisation bodies, industry-regulator groups etc., may be accepted based upon demonstration of appropriate applicability and substantiation, as agreed with the competent authority.

IMPORTANT REMINDER: AM is a rapidly developing technology supported by many developing industry guideline documents, but lacking regulatory guidance in any detail. Therefore, this CM revision process attempts to periodically document and share progress relative to EASA regulatory expectations and does not represent a complete or final EASA position. EASA is of the opinion that this approach is preferable, i.e. preferable to not doing so, for the purposes of visibility and for progressing safe development and use of AM in certified parts. 

Section 2 content ONLY provides background and context for the developing Policy, NOT Policy. 

Section 3 content provides Policy. This revision addresses early engagement with EASA regarding AM and also applications of no or low criticality (Class C and D). 

NOTE: This CM revision is supported by a Supplemental document intended to record supporting discussion necessary to provide context for this revision content, and also for potential future CM revision evolutions. Such supplemental documents are considered to be appropriate in the absence of complete and published reference documentation existing elsewhere, as may be typical for new and developing technologies and applications, whilst maintaining a more acceptable and manageable format for the main CM document.