FAA 14 CFR § 45.15 Marking requirements for PMA articles, TSO articles, and Critical parts.

https://www.govinfo.gov/content/pkg/CFR-2010-title14-vol1/pdf/CFR-2010-title14-vol1-sec45-15.pdf

(a) PMA articles. The manufacturer of a PMA article must permanently and legibly mark—

(1) Each PMA article, with the PMA holder’s name, trademark, symbol, or other FAA approved identification and part number; and

(2) The letters ‘‘FAA–PMA’’.

FAA AC 43-213A

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43-213A_CHG_1.pdf

1. PURPOSE. This advisory circular (AC) provides information and guidance on developing procedures for part marking and part re-marking when performing maintenance, alteration, and fabrication, including the fabrication of owner- or operator-produced parts.

7. c. Maintenance Providers.

(4) Maintenance providers, including owners and operators, fabricating aircraft parts to be consumed during maintenance and alteration should clearly identify those articles with an additional permanent and legible marking.

(a) The marking should include the following:

• The name, trademark, or symbol of the FAA certificate holder (fabricator) under whose control the fabrication occurred;

• A unique part number that clearly distinguishes the fabricated part; and

•The original manufacturer’s part number, if removed as a result of the fabrication.

(5) Due to the limited duration of maintenance record retention requirements, the FAA encourages maintenance providers that independently develop major repairs and major alterations (i.e., those not contained in the manufacturer’s maintenance manual, instructions for continued airworthiness (ICA), or other manufacturer’s service information) to provide a unique marking, such as the name, trademark, designator, or symbol of the FAA certificate holder, to parts that have undergone this work. This information would provide subsequent maintenance providers with an indication that the part may require special handling to ensure continued airworthiness (such as the use of inspection criteria developed by the person who performed the major repair or major alteration).

“FAA-PMA” and/or part number prefix or suffix:

Unique markings not typical for an OEM Repair:

European Union Aviation Safety Agency

https://www.easa.europa.eu/sites/default/files/dfu/Easy%20Access%20Rules%20for%20Part-21.pdf

https://www.easa.europa.eu/the-agency/faqs/initial-airworthiness

Should parts fabricated under a maintenance approval (Part 145) be marked with an EPA (European Part Approval) marking in accordance with Part 21A.804(a)(3)?

A Part 145 approved organisation can only fabricate parts for its own use in accordance with approved design data (145.A.42(c)). If that data comes from the Type Certificate holder; 21A.804(a)(3) would not be applicable and those parts will not need EPA marking. If the data comes from a Supplemental Type Certificate holder, minor change approval holder or repair approval holder, the parts will have to be marked as prescribed in the applicable data, which should include an EPA marking since 28/3/2004.

Why and how must Parts and Appliances be marked, when are the letters EPA required, and which exceptions are acceptable?

To comply with EASA Part-21, Subpart D, 21.A.109, Subpart E, 21A.118A (b) and Subpart M, 21A.451(a) and (b), it is the obligation of the respective Holders of a Minor Change Approval, a STC, or a Major Repair Design Approval, to specify the required markings, including EPA letters as applicable, in their Design (read, ‘Approved Data’), according EASA Part-21, Subpart Q.

Subpart Q, 21.A.804(a), and related GM, require proper identification of each Part and Appliance that is designed or redesigned, including parts designed to be incorporated in repairs (21A.451), by ‘permanent and legible marking’ hereof, and is applicable for Design Organisations and Manufacturers.

21.A.804(a) 1 and 2 clearly require marking of Parts and Appliances with ‘name, trademark, or symbol identifying the Manufacturer’ and ‘Part number’, as defined in the applicable Design Data.

According to the GM the Design Approval Holder shall identify in all its Design (TC, STC, ETSO, Repair, Change) approved after 28 December 2009, how the Manufacturer has to mark subject Parts and Appliances in accordance with 21A.804(a) 1; which can be limited to identifying a marking field and the method, without prescribing the actual text or symbols.

21.A.804(a) 3 requires additionally marking with the letters ‘EPA’ of all parts produced (manufactured) in accordance with data ‘not belonging to the TC holder of the related product’.

Each interchangeable or removable Part or Appliance that is manufactured in accordance with a design issued by the Design Organisation, shall be permanently and legibly marked according to 21.A.804. The EPA marking was introduced in 2004; this was done to clearly identify any ‘not original’ Part, (which means any Part or Appliance not designed by the TC- or ETSO- Approval Holder), as a trigger for Maintenance Organisations and Accident or Incident investigators, in the light of Continuing Airworthiness. The intention was certainly not to require adding of the letters ‘EPA’ to mark repairs. In this context, EPA marking only applies to the new designed and manufactured parts to be incorporated in the repair. Especially where repairs have an impact on interchangeability, identification of incorporated new Parts is very important, and DO Procedures should address this item.

The only accepted exception with regard to Marking (including EPA), is defined in 21.A.804(b). This subparagraph offers the possibility to not physically mark the Part of Appliance, when it is too small or when marking hereof is otherwise impractical, but only after “Agency agreement”. This wording allows an Applicant/Holder of a Design and the Agency to further define in detail how this ‘agreement’ can be obtained and will be formalised. DOATL should however ensure that the DOA Applicant/Holder reflects this approach in its DO Handbook or Procedures, requiring at least a justification of the reason for not marking physically, and details of the alternative way chosen for the identification, in accordance with 21A.804(b), to know on the authorised release document accompanying the Part or Appliance, or on its container.