EASA Part 21 — Airworthiness and Environmental Certification

EASA Part 21 — Airworthiness and Environmental Certification

Issuing body / enforcer: European Union Aviation Safety Agency (EASA), under the EU Basic Regulation 2018/1139. Legal substance: Commission Regulation (EU) No 748/2012, Annex I — "Part 21." Jurisdiction: EU member states, plus EFTA states participating in EASA (Norway, Iceland, Liechtenstein, Switzerland under bilateral arrangements). Products certified under Part 21 are accepted worldwide through bilateral agreements (e.g., FAA-EASA Technical Implementation Procedures). Cross-discipline note: The Quality/Reliability discipline's Subpart G (Production Organisation Approval) record points here — this is the canonical brief. All references to "EASA Part 21" in the catalogue resolve to this file.

What it is

Part 21 is the EU's rulebook for how aircraft, engines, propellers, parts, and appliances are proven airworthy and environmentally acceptable (noise and emissions) before they fly, and how design and production organisations earn the privilege of doing that proving work under their own oversight systems. It is the European counterpart to FAA 14 CFR Part 21, and the two are kept interoperable through bilateral validation — an FAA type certificate can be validated by EASA (and vice versa) without a full re-certification.

The regulation is divided into Subparts, each with a letter:

• Subpart A — general provisions.
• Subpart B — Type Certificates (TC) and Restricted TCs.
• Subpart C — changes to TCs (major vs. minor).
• Subpart D — changes to TCs by holders other than the TC holder (Supplemental Type Certificates, STCs — historically Section A / Subpart E for ETSOs handled differently).
• Subpart E — Supplemental Type Certificates.
• Subpart F — production without a Production Organisation Approval (one-off / limited production).
• Subpart G — Production Organisation Approval (POA): the approval that lets a company manufacture products, parts, and appliances in conformity with approved design data under a controlled production quality system.
• Subpart H — Certificates of Airworthiness (CoA) and Restricted CoA.
• Subpart I — noise certificates.
• Subpart J — Design Organisation Approval (DOA): the approval that lets a company hold design approvals (TCs, STCs, major changes/repairs) under its own design assurance system.
• Subpart K — parts and appliances.
• Subpart L — (reserved / historical).
• Subpart M — repairs (major vs. minor).
• Subpart N — (historical).
• Subpart O — ETSO (European Technical Standard Order) authorisations.
• Subpart P — permits to fly.
• Subpart Q — identification of products, parts, appliances.

Two additional certification specifications ride on top: CS-23/CS-25/CS-27/CS-29 (the airworthiness codes for each aircraft category, EASA's equivalent of FAR Parts 23/25/27/29) and the environmental requirements (ICAO Annex 16 noise and emissions standards, implemented through Part 21 Subpart I and the CS codes).

Scope: who it applies to

Anyone who wants to design, build, or modify a civil aircraft or its parts for use in EASA member states:

• Design organisations seeking DOA (Subpart J) — mandatory for TC holders.
• Production organisations seeking POA (Subpart G) — mandatory for serial production.
• Type Certificate applicants — OEMs certifying new aircraft types (e.g., Airbus, or eVTOL developers working through EASA's VTOL special conditions).
• STC and repair design holders, ETSO authorisation holders, and operators needing permits to fly for non-compliant aircraft (e.g., ferry flights, flight test).

Trigger: any new type design, any major change or repair to a type design, serial production of certified products, or operation of an aircraft that does not meet full certification requirements.

Key requirements and compliance obligations

1. Design assurance (Subpart J / DOA). A DOA holder must operate a design assurance system with independent compliance verification, configuration control, and a continuing-airworthiness function that monitors in-service experience and issues service bulletins and airworthiness directives support. The head of the design organisation signs a statement of compliance for each design approval.
2. Type certification basis. EASA establishes the certification basis: the applicable CS codes at the amendment level in effect at application, plus any special conditions (novel features, e.g., distributed electric propulsion) and equivalent-safety findings. The applicant must demonstrate compliance for every requirement — through analysis, test, or a combination — documented in compliance checklists.
3. Environmental certification. Noise certification (Subpart I) against ICAO Annex 16 Volume I standards and emissions/fuel-venting certification against Annex 16 Volumes II–IV. Recent CAEP amendments are implemented through AMC/GM updates (see "Live changes" below).
4. Production conformity (Subpart G / POA). A POA holder must demonstrate that every product, part, and appliance conforms to the approved design data and is in condition for safe operation. This requires a documented quality system covering supplier control, incoming inspection, manufacturing processes, calibration, non-conforming material control, and issuance of EASA Form 1 (authorised release certificates). EASA (or the national authority) audits the POA holder and can suspend or revoke the approval.
5. Continued airworthiness and occurrence reporting. DOA and POA holders must collect and analyse in-service data, report occurrences under Regulation (EU) No 376/2014, and cooperate on airworthiness directives. The 2022 SMS/occurrence-reporting embodiment (AMC/GM Amendment 14) made safety management explicit in Part 21 organisations.
6. Changes and repairs. Major changes require EASA approval (or DOA-privilege approval within agreed scope); minor changes can be approved under DOA privilege. Classification of major vs. minor is itself a regulated determination.
7. Permits to fly (Subpart P). For aircraft not meeting full certification (test, ferry, exhibition), the operator must obtain a permit to fly with approved flight conditions.

Penalties and consequences of non-compliance

EASA and national competent authorities can suspend or revoke DOAs, POAs, type certificates, and individual certificates of airworthiness. Operating a non-airworthy aircraft, or manufacturing non-conforming parts, exposes the organisation to national enforcement action — in EU member states this typically means administrative fines and, for serious safety violations, criminal liability under national aviation law. Fraudulent issuance of EASA Form 1 or falsified conformity records has led to prosecutions in multiple member states. At the commercial level, loss of a POA or DOA is effectively a shutdown of the certification business, and invalid type certificates ground fleets — the 737 MAX grounding demonstrated the scale of commercial exposure when a certification basis is challenged, even under the FAA system.

Version / edition status and live changes (verified 2026-09-30)

• Consolidated text: EASA publishes "Easy Access Rules for Initial Airworthiness and Environmental Protection" (Regulation (EU) No 748/2012). A Revision from November 2025 is current, incorporating: Delegated Regulation (EU) 2024/1108 and Implementing Regulation (EU) 2024/1110 (initial airworthiness of certifiable unmanned aircraft systems), Delegated Regulation (EU) 2025/1065 (updated environmental protection references, correcting the regulation), Implementing Regulation (EU) 2025/2293, and ED Decision 2025/016/R (AMC/GM to Part 21 — Issue 2, Amendment 17).
• AMC and GM to Part 21 — Issue 2, Amendment 18, published 6 July 2026 via ED Decision 2026/005/R, covering: the airworthiness review process, import of aircraft from other regulatory systems, review of Subpart H, and alignment of the Basic Regulation implementing rules and AMC/GM with occurrence-reporting Regulation (EU) No 376/2014. This supports implementation of Regulations (EU) 2026/100 and 2026/56 — aimed at raising standards for importing aircraft from non-EU regulatory systems and reducing administrative burden for airworthiness review certificates.
• eVTOL / new air mobility: EASA continues certification work under VTOL special conditions with Part 21 as the procedural backbone (e.g., type certification applications for piloted eVTOL aircraft); rulemaking streams (RMT.0731, RMT.0230) are adapting the framework to electric/hybrid propulsion and drones.
• Flag (unverified detail): the exact amendment level of individual CS codes (CS-25, CS-23, CS-E, etc.) changes frequently; practitioners should check the current CS amendment on the EASA website rather than relying on this brief.

Related certifications (from the engineering catalogue)

Flagship/license certifications in the Aerospace discipline: FAA Airframe and Powerplant (A&P) Mechanic Certificate and Chartered Engineer (CEng) via the Royal Aeronautical Society. Neither directly tests or requires Part 21 knowledge — A&P is a US maintenance-licensing credential (operating under 14 CFR Parts 43/65, not the EASA system) and CEng is a professional-registration credential. The certifications that genuinely operate inside Part 21 (EASA Part-66 aircraft maintenance licences, Part-147 training) are outside this catalogue's flagship set. Practitioners seeking DOA/POA roles typically build Part 21 competence through employer training and EASA/industry courses, not through the two flagship credentials above.

Honest flags

• Penalty amounts are jurisdiction-dependent (national law) and no single EU-wide fine schedule exists — the enforcement description above is structural, not quantified.
• Subpart lettering follows the consolidated 748/2012 structure; historical renumbering (e.g., former Section A/Subpart E for STCs) can confuse older references.
• Drone-related Part 21 provisions (certifiable UAS under 2024/1108 and 2024/1110) are recent — implementation practice is still maturing.

Original ETS reference writing, verified against public sources on 2026-09-30. Thin sourcing is flagged inline. Not legal advice — confirm current editions with the issuing body.