NAS 410 / EN 4179 Compliance for Inspection Service Providers
NDT providers and in-house NDT functions serving aerospace manufacturing, maintenance, repair and overhaul — engine and airframe shops, casting and forging suppliers, and independent NDT houses on aerospace approved-supplier lists. Primes flow the requirement down through purchase orders, and Nadcap audits it under AC7114. Personnel are qualified under employer-based certification, so a contracted Level III can sign the written practice and administer examinations for the firm.
Firms selling into both US and European aerospace supply chains have to satisfy the NAS 410 and EN 4179 halves consistently. NAS 410 sets minimum requirements for qualifying and certifying Level 1, Level 2, Level 3 and Senior Level 3 personnel performing NDT, NDI or NDE in the aerospace manufacturing, service, maintenance and overhaul industries. Revision 6 was released by AIA and Accuris on 1 December 2025 and introduces a new Appendix D creating an additional pathway to Level 3 qualification, under which Level 2 personnel complete designated NDT activities that earn points toward qualification. EN 4179 is technically equivalent as published; the 2026 edition superseded EN 4179:2021 and carries annexes on the Level 3 recertification credit system, Level 1-limited personnel, and NANDTB requirements. Personnel certified to earlier revisions need not recertify until their current certification expires.
Source: AIA press release, 'AIA and Accuris Release NAS410 Revision 6, Advancing Aerospace Safety and Workforce Development' (aia-aerospace.org) — release date 1 December 2025, Appendix D points-based Level 2 to Level 3 pathway, Accuris as sole source for AIA subscription content. NAS 410 Rev 5 (2020) scope and the four levels (Level 1, 2, 3, Senior Level 3) from standard catalogue records. NAS 410 paragraph 4.5 'Responsible Level 3' wording quoted from ndt.net technical forum discussion citing the standard text; treat the paragraph number as indicative and confirm against Rev 6. EN 4179:2021 (BS/DS editions) and EN 4179:2026, listed by BSI and DIN distributors as the current edition published 2026, superseding EN 4179:2021 — verified through distributor catalogue listings rather than the CEN portal. FAA/EASA harmonisation and technical equivalence of EN 4179 and NAS 410 from published NDT qualification literature and the FAA's NDT memorandum for production approval holders. Nadcap AC7114 audit content, top nonconformances and the Supplier Merit Program 12/18/24-month intervals from PRI (p-r-i.org) course outlines and Nadcap programme material, plus Quality Magazine's Nadcap NDT audit perspective. Checked August 2026.
| Item | What applies | Why it matters |
|---|---|---|
| Authority | Aerospace Industries Association (AIA) publishes NAS 410, distributed through Accuris. EN 4179 is prepared by ASD-STAN and published through CEN. Enforcement is by the airframe and engine primes through purchase-order flow-down, by the Performance Review Institute (PRI) through Nadcap audits to AC7114, and by aviation regulators — the FAA treats personnel qualified under EN 4179 as technically equivalent to NAS 410. National Aerospace NDT Boards (NANDTBs) operate in countries that have established them. | The body that issues, audits and can withdraw |
| Applies to | NDT providers and in-house NDT functions serving aerospace manufacturing, maintenance, repair and overhaul — engine and airframe shops, casting and forging suppliers,. | Whether this binds your firm at all |
| Personnel certification | Employer-based — the firm certifies its own, under a qualified Level III | Decides whether an outsourced Level III can sign for you |
| Renewal | Personnel certification expiry is set by the employer's written practice; NAS 410 states that personnel certified to previous revisions of NAS 410 or EN 4179 need not recertify to the requirements of the new revision until their current certification expires. The company-level cycle is separate and defined by Nadcap: the first reaccreditation audit falls within twelve months of the initial audit, after which the Supplier Merit Program can extend the interval to 18 or 24 months depending on audit performance. | Diarise from the certificate date, not from memory |
| Methods in scope | PT, MT, UT, PAUT, RT (film), RT-D / digital radiography | Each method needs its own procedure and qualified personnel |
| Industries | Aerospace manufacturing, Aviation MRO and overhaul, Engine components, Castings and forgings, Defence aviation | Where this regime shows up in contracts |
Who does NAS 410 / EN 4179 apply to?
NDT providers and in-house NDT functions serving aerospace manufacturing, maintenance, repair and overhaul — engine and airframe shops, casting and forging suppliers, and independent NDT houses on aerospace approved-supplier lists. Primes flow the requirement down through purchase orders, and Nadcap audits it under AC7114. Firms selling into both US and European aerospace supply chains have to satisfy the NAS 410 and EN 4179 halves consistently.
Can an outsourced Level III sign for NAS 410 / EN 4179 compliance?
Yes. NAS 410 / EN 4179 accepts employer-based certification, which places the obligation on the employer and allows a contracted Level III to write and sign the written practice, approve procedures and administer examinations. The Level III must be qualified in each method they sign for, and the employer still owns the records.
What documents does a NAS 410 / EN 4179 audit ask for?
Written practice for the training, qualification and certification of NDT personnel, approved by the Responsible Level 3, Written designation of the Responsible Level 3, plus that person's Level 3 certification records and evidence of knowledge of the employer's codes and specifications, Individual qualification files: training, experience, General, Specific and Practical examination results, and vision test records, Documented determination by the Responsible Level 3 — or by a NANDTB where one applies — of the adequacy and equivalency of experience carried in from a prior employer or programme, NDT procedures and work instructions for each method and technique, approved by the Responsible Level 3. Auditors open records before they open manuals, because a manual describes intent while records show practice. The most common failure is a documented system that does not match what the technicians actually do.
How often is NAS 410 / EN 4179 renewed?
Personnel certification expiry is set by the employer's written practice; NAS 410 states that personnel certified to previous revisions of NAS 410 or EN 4179 need not recertify to the requirements of the new revision until their current certification expires. The company-level cycle is separate and defined by Nadcap: the first reaccreditation audit falls within twelve months of the initial audit, after which the Supplier Merit Program can extend the interval to 18 or 24 months depending on audit performance. Firms that diarise renewal from the certificate date rather than from the last audit avoid the lapse that forces a full reapplication.
What are the most common NAS 410 / EN 4179 findings?
Self-audit not performed, or performed without all applicable job audits — consistently among the most-cited AC7114 nonconformances, Required pre-audit package not sent to the auditor 30 days before the audit, Corrective actions from the previous Nadcap audit no longer implemented at the following audit, Calibration requirements not flowed down to subcontracted calibration or subcontracted NDT services. These recur because they are records problems rather than capability problems — the work is being done correctly and the evidence is not being kept.
Which NDT methods does NAS 410 / EN 4179 cover?
PT, MT, UT, PAUT, RT (film), RT-D / digital radiography, ET. Each method in scope needs its own approved procedure and personnel qualified in that specific method; a Level III qualified in ultrasonics cannot sign for radiography.
Personnel certification under NAS 410 / EN 4179
Employer-based, with a named accountable individual. The employer shall identify in writing a Responsible Level 3 to act on its behalf in matters regarding the NDT qualification and certification process; that person shall be certified as a Level 3 in one or more NDT methods and shall have thorough knowledge of the written instructions, codes, specifications and standards the employer uses. NAS 410 does not require an ASNT NDT Level III certificate, though an employer's written practice may accept one as evidence of the General examination. Contracting the Responsible Level 3 role to an outside agency is common and workable — but only the employer certifies personnel, and in Europe a NANDTB may need to approve the Level 3.
The audit sequence
- Apply for Nadcap accreditation through PRI's eAuditNet / EANSM platform and select the AC7114 checklists matching the methods and techniques actually performed
- Complete the self-audit against those checklists including all applicable job audits, and send the required package to the auditor 30 days before the audit
- On-site audit covering scope and general information, customer and procurement requirements, internal NDT audits, personnel proficiency and certification records, examinations and vision testing, Level 3 responsibilities and inspection status control — plus live job audits on real parts
- Auditor uploads nonconformance reports; the supplier responds with root cause and corrective action, reviewed by PRI staff engineers
- The Nadcap NDT Task Group votes to accredit, fail, or issue merit
- First reaccreditation audit within twelve months of the initial audit; subsequent reaccreditation intervals extend to 18 or 24 months under the Supplier Merit Program based on audit performance
Documents an auditor asks for
- Written practice for the training, qualification and certification of NDT personnel, approved by the Responsible Level 3
- Written designation of the Responsible Level 3, plus that person's Level 3 certification records and evidence of knowledge of the employer's codes and specifications
- Individual qualification files: training, experience, General, Specific and Practical examination results, and vision test records
- Documented determination by the Responsible Level 3 — or by a NANDTB where one applies — of the adequacy and equivalency of experience carried in from a prior employer or programme
- NDT procedures and work instructions for each method and technique, approved by the Responsible Level 3
- Customer and procurement requirement flow-down records showing which prime specifications apply to which work
- Internal NDT audit records, plus evidence that corrective actions from the previous Nadcap audit remain implemented
- Equipment calibration, system performance check and process control records, including calibration requirements flowed down to subcontractors
- The completed AC7114 self-audit package, including all applicable job audits, sent to the auditor before the audit
Findings firms get against NAS 410 / EN 4179
- Self-audit not performed, or performed without all applicable job audits — consistently among the most-cited AC7114 nonconformances
- Required pre-audit package not sent to the auditor 30 days before the audit
- Corrective actions from the previous Nadcap audit no longer implemented at the following audit
- Calibration requirements not flowed down to subcontracted calibration or subcontracted NDT services
- Written procedure and observed practice disagree during a job audit — the technique the operator ran is not the technique the procedure specifies
- Equivalency of experience carried in from a prior employer or programme not evaluated and documented by the Responsible Level 3 or the NANDTB
- Written practice not approved, or not re-approved, by the current Responsible Level 3 after a personnel change
- Process timing steps missed during a job audit — PRI's published lists cite eddy current step-one timing among the recurring job-audit nonconformances
- US firm holding only a NAS 410 Level 3 finds it insufficient for a European customer who requires a NANDTB-approved Level 3
Related: the NAS 410 / EN 4179 overview, outsourced ASNT Level III cover, written practice development, NDT procedure development, a programme gap assessment, interim Level III cover.