FAA STC Certification Process & Bilateral Considerations

Sofema Aviation Services (SAS) www.sassofia.com considers the key elements of the FAA Certification process together with Bilateral Considerations

Introduction – Supplemental Type Certificates (STCs)

STC Issuance by the FAA

The process begins with the FAA issuing an STC for a modification to a type-certified aircraft or component. The STC holder (the entity developing the modification) must demonstrate compliance with FAA regulations found in Title 14 of the Code of Federal Regulations (14 CFR). The steps include:

• Design and Engineering Analysis: The applicant must provide detailed technical data demonstrating that the modification is safe and does not negatively impact the aircraft’s airworthiness.
• Testing: Depending on the nature of the modification, flight tests, ground tests, or simulations may be required to validate the performance and safety of the modification.
• Certification: The FAA evaluates the data, conducts reviews, and issues the STC once all requirements are met.

Bilateral agreements between the FAA and EASA provide for mutual recognition of certifications, enabling manufacturers and operators to obtain approvals more quickly.

• The streamlined validation process allows for modifications to aircraft and components to be certified across both jurisdictions, enabling easier market access and reducing operational downtime.

Important Note – Applicants Should be aware of regulatory differences and ensure that their modifications meet both FAA and EASA standards.

STCs are issued when modifications are made to an already type-certified aircraft or component.

• These changes can include anything from major alterations like engine upgrades to smaller modifications such as avionics or cabin reconfigurations.
• In the context of the bilateral agreements between EASA (European Union Aviation Safety Agency) and Transport Canada Civil Aviation (TCCA), the certification process for STCs is crucial as it ensures that these modifications are recognized and accepted across both regulatory environments.

EASA STC Validation

When an STC is issued by the FAA for a U.S.-registered aircraft or component, the EASA validation process is simplified under the bilateral agreement. The STC applicant can submit the FAA-approved STC data to EASA for validation, avoiding a full recertification process.

Factors in STC Validation

Differences in Regulatory Standards

While the FAA and EASA have harmonized many of their certification standards, there are still some differences, particularly in areas such as:

• Environmental regulations (e.g., noise and emissions standards).
• Cybersecurity and electronic systems, where EASA may impose stricter requirements.
• Operational standards related to safety margins and performance parameters.

These differences can affect the validation process, requiring applicants to demonstrate compliance with both sets of standards.

EASA may request additional documentation or testing depending on the complexity of the modification, but in many cases, the process is expedited through the agreement

The validation process generally involves three levels, depending on the complexity of the STC:

• Basic STCs – These are simpler modifications (e.g., minor avionics upgrades or small structural changes). Under the bilateral agreement, EASA relies on FAA approval and only conducts a minimal technical review, verifying compliance with European standards. EASA may accept the FAA’s STC without additional testing, provided the modification is routine and presents no novel or high-risk elements.
• Complex STCs If the modification is more complex (e.g., engine changes or advanced avionics), EASA will perform a detailed technical review of the FAA-approved STC. EASA may request additional documentation, compliance reports, or technical data to ensure the modification meets European Certification Specifications (CS).
• Novel or High-Risk STCs For modifications involving new technologies or high-risk elements (e.g., fly-by-wire systems or advanced autopilot technologies), EASA may require additional testing and verification beyond what the FAA conducted. This level of validation often involves cooperation between the FAA and EASA to address any specific technical or regulatory differences.

Post-Certification and Continued Airworthiness

Once EASA has validated the FAA-issued STC, the modification can be applied to aircraft registered in Europe. The STC holder has ongoing obligations to ensure the continued airworthiness of the modified aircraft, including:

• Service Bulletins (SBs): Issued to operators to address any post-certification issues or improvements.
• Airworthiness Directives (ADs): Issued by EASA (or FAA) to address safety concerns if the modification introduces new risks or deficiencies.

Additionally, any subsequent design changes to the STC must be validated by both FAA and EASA if they affect the certified aspects of the modification.

Next Steps

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Sofema Aviation Services (SAS) and Sofema Online (SOL) provide regulatory training related to Bilateral relationships between EASA – FAA – TCAA and UK CAA. Please see the websites or email team@sassofia.com.