Sofema Aviation Services (SAS) considers key features of the FAA STC Process
Introduction
- The Supplemental Type Certificate (STC) process is a critical regulatory mechanism ensuring that modifications to type-certified products are safe, effective, and compliant with FAA standards.
- Each participant—from the applicant to the FAA, STC holders, and aircraft operators—has specific roles and responsibilities in ensuring the successful approval and implementation of STCs.
What is an STC?
The Supplemental Type Certificate (STC) process under 14 CFR Part 21, Subpart E outlines the requirements, issuance, privileges, and responsibilities associated with modifications to previously type-certified aircraft, engines, or propellers. Below is a detailed discussion of the roles and responsibilities involved.
Applicability (§ 21.111)
This subpart applies to major modifications to type-certified products that require FAA approval but do not necessitate a new Type Certificate (TC). STCs cover significant design changes, including structural alterations, avionics upgrades, or new engine installations.
Roles and Responsibilities – Applicant for an STC
(§ 21.113 Requirement for STC, § 21.115 Applicable Requirements)
- Who can apply? Any individual or organization seeking approval for a major modification to an existing type-certified product.
- Application Process:
- Submit an application to the FAA with details of the modification.
- Demonstrate compliance with applicable airworthiness and environmental regulations (e.g., noise and emissions requirements in Parts 34, 36, and 38).
- Conduct tests and analyses required by the FAA.
- Compliance with regulations:
- Ensure that all modifications align with the applicable regulatory standards.
- Provide documentation and show conformity with § 21.101 (Applicable Regulations for Type Certificate Changes).
FAA (Federal Aviation Administration) – (§ 21.117 Issue of STCs)
- Evaluation and approval:
- Review applications for compliance with regulations.
- Conduct safety assessments and testing evaluations.
- Issue the Supplemental Type Certificate (STC) if the applicant meets all requirements.
- Design Change Classification:
- Determine whether a change is significant enough to require an STC instead of a minor modification.
Holder of a Supplemental Type Certificate – (§ 21.119 Privileges, § 21.120 Responsibilities)
- Privileges of the STC holder:
- Allows the holder to implement and market the approved modification.
- If the holder also holds the Type Certificate, they can integrate modifications without obtaining a new STC.
- Responsibilities:
- Provide written permission for alterations using their STC (§ 21.120).
- Maintain compliance with all airworthiness standards.
- Ensure all affected products conform to the approved design.
Aircraft Owner/Operator Implementing an STC
- Ensure that any modification performed using an STC is done by a certified repair station or under FAA-approved maintenance.
- Obtain and retain documentation proving that the modification has been properly installed and maintained.
Maintenance and Engineering Teams
- Maintain the continued airworthiness of modified aircraft.
- Ensure proper implementation of service bulletins and airworthiness directives related to the STC.
Key Aspects of the STC Process – STC Approval and Issuance (§ 21.117)
- The FAA grants an STC when it determines that:
- The modification complies with all applicable airworthiness standards.
- The STC applicant has demonstrated the design change does not adversely affect safety.
Responsibilities of the STC Holder (§ 21.120)
- STC holders must provide written permission to any individual or company seeking to use the STC to perform a modification.
- They must ensure that the modification remains compliant with all applicable FAA regulations throughout its operational life.
STC Privileges (§ 21.119)
- The STC holder may sell and distribute their approved design modifications.
- If they also hold the Type Certificate, they can apply changes without the need for a separate STC.
Next Steps
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SAS blogs, Supplemental Type Certificate (STC), FAA (Federal Aviation Administration), 14 CFR part 21, Subpart E, FAA STC Process, Applicability (§ 21.111), major modifications, 21.117 Issue of STCs, § 21.119 Privileges, § 21.120 Responsibilities, STC Approval and Issuance (§ 21.117)
