AMENDMENT TO THE REGULATION ON AIRWORTHINESS AND ENVIRONMENTAL CERTIFICATION OF AIRCRAFT AND RELATED PRODUCTS, PARTS AND APPLIANCES (SHY-21)

The Regulation on the Airworthiness and Environmental Certification of Aircraft and Related Products, Parts and Appliances (“Updated SHY-21”) was published in the Official Gazette on 28 April 2025 and entered into force on the same date.
Pursuant to Article 14 of the Updated SHY-21, the former Regulation on the Airworthiness and Environmental Certification of Aircraft and Related Products, Parts and Appliances (“Former SHY-21”), published in the Official Gazette dated 20 August 2013 and numbered 28741, has been repealed.

A comparison between the Updated SHY-21 and the Former SHY-21 reveals that while the core regulatory framework has largely been preserved, the purpose, scope, and legal basis have been expanded, and several concepts have been further detailed. The key changes introduced under the Updated SHY-21 are summarized below:

1. Expansion of Purpose and Scope

Articles 1 and 2 of the Updated SHY-21 expand the scope to explicitly cover not only the airworthiness of aircraft and related products, parts, and appliances but also compliance with environmental certification processes, including noise and emission standards. Additionally, regulations regarding the authorization of design and production organizations have been incorporated into the scope.

2. Reorganization of the Legal Ground

As with the Former SHY-21, the Updated SHY-21 cites the Turkish Civil Aviation Law No. 2920 and the Chicago Convention as its underlying legal ground. In addition, to align with international standards, references to ICAO Annex 8 and Annex 16, and in parts, to EASA Part-21, are included. Unlike the Former SHY-21, EASA Part-21 is not directly referred as a primary legal ground; instead, Article 13 aims to achieve general compliance with European Union legislation.

3. Updates to Definitions and Concepts

The Updated SHY-21 introduces new definitions, including “Operational Suitability Data,” “Special Flight Permit,” and “Restricted Type Certificate,” while revising some existing definitions (such as “Type Certificate” and “Certificate of Airworthiness”) to align more closely with international standards. This aims to provide greater clarity and consistency in practical implementation.

4. Procedural Changes to Certification Processes

The Updated SHY-21 provides more detailed regulations for the issuance, amendment, suspension, and revocation of certificates, including type certificates, supplemental type certificates, certificates
of airworthiness, restricted certificates of airworthiness, and special flight permits.

For instance, under the Former SHY-21, issuing a restricted certificate of airworthiness required a “reasonable number” of aircraft of the same type, whereas under the Updated SHY-21, a specific threshold is introduced: the certificate may now be issued if there are five or more aircraft of the same type.

Certification procedures for parts and appliances have also been updated, and compliance with environmental protection requirements has been explicitly incorporated into the certification process.
Moreover, the use of an Information Management System has been made mandatory during organizational audits.

The Directorate General may also require subcontractors engaged in design or production activities to obtain separate organizational approvals, based on an evaluation of the organization’s scope of work, the criticality of the work performed, its size, and the subcontractor relationships.

5. Further Detailing of Environmental Protection Obligations

The Updated SHY-21 mandates that products, parts, and appliances comply with ICAO Annex 16: Part I (Aircraft Noise), Part II (Aircraft Engine Emissions), and Part III (CO₂ Emissions).
Additionally, the requirements for data and documentation to be submitted as part of the environmental certification process have been elaborated.

6. Provisions on the Acceptance of Foreign Certifications

Under the Updated SHY-21, certificates issued by EU Member States before 28 September 2003, falling within the scope of the Former SHY-21, may be accepted following an assessment by the Directorate General, provided that the conditions set out in Commission Regulation (EU) No. 748/2012 are duly considered.
Approval applications from organizations located abroad will be assessed by the Directorate General, provided that the relevant country has signed a bilateral agreement with Türkiye.

7. Clarification of Inspection Powers and Administrative Sanctions

The authority of the Directorate General in certification processes has been expanded, and inspection procedures for organizations and products have been comprehensively detailed. In cases of non-compliance with the Updated SHY-21, administrative sanctions and the revocation of certificates may be imposed under the Turkish Civil Aviation Law No. 2920.

Furthermore, the sanctions system has been formalized:
• In the event of a Level 1 finding (significant deficiency or fault), if corrective action is not taken within 21 business days from the date of detection, the relevant certificate may be suspended.
• In the event of a Level 2 finding, the organization will be granted a maximum of three months to remedy the deficiencies. If it is determined that the deficiencies cannot be remedied within this

period, the organization may submit a corrective action plan at least 10 days before the end of the deadline, subject to the Directorate General’s approval, and may be granted an additional period of up to three months. Failure to correct the deficiencies may result in certificate revocation and suspension of activities.
In light of these changes, all organizations engaged in design, production, certification, and export activities are strongly advised to review and update their internal processes in compliance with the Updated SHY-21.