STC Risk-Based Validation FAA, EASA, TCCA, and ANAC

February 20, 2026

Blog

Sofema Aviation Services (SAS) Considers the Bilateral Treatment of STCs.

The goal of the Certification Management Team (CMT) is to move away from “proving safety twice” (once to the FAA, once to EASA) and toward a system where the Validating Authority (VA) trusts the Certifying Authority (CA) completely.

Here, we provide a detailed breakdown of the Validation Principles and the specific criteria under which EASA will accept an FAA STC without technical review.

The Three Tiers of Validation

To understand “acceptance without review,” you must distinguish between the three levels of scrutiny applied by the CMT partners (specifically, FAA and EASA under TIP Revision 6/7).

1.Reciprocal Acceptance: The Validation Authority (e.g., EASA) does not issue its own certificate, as the FAA approval is automatically recognized as valid. The outcome is zero additional paperwork, with the FAA STC or Form accepted as sufficient legal data for operation in Europe.

2. Streamlined Validation (Basic STC): The Validation Authority issues its own STC but performs no technical review, limiting the process to administrative and documentation checks only. The outcome is an administrative EASA STC issued within approximately three to four weeks, with standard validation fees applied.

3. Technical Validation (Non-Basic STC): The Validation Authority issues its own STC following a focused review of specific technical areas, with the assessment limited to critical items under a defined Level of Involvement. The outcome is a technical EASA STC issued after a longer review period—often several months—together with higher fees and hourly technical charges.

When does EASA accept without review? (“Basic” Classification)

Under the FAA-EASA Technical Implementation Procedures (TIP), an FAA STC is classified as either Basic or Non-Basic.
If an STC is Basic, it qualifies for Streamlined Validation (Tier 2 above). EASA will issue the certificate without asking any technical questions.

The “Non-Basic” Trigger List (Criteria for Review)

An STC is automatically Basic (accepted without review) unless it triggers one of the following “Non-Basic” criteria. If your STC has any of these, EASA will want to review it:

New or Novel Features: Technology that the FAA or EASA has not previously certified (e.g., a new type of lithium battery or HUD).
Environmental Impact: Changes to Noise or Emissions levels (requires a new EASA environmental certificate).
Airworthiness Limitations: Changes to the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness (ICA).
Exemptions & Special Conditions: The design required an FAA Exemption, Special Condition, or Equivalent Level of Safety (ELOS) finding.
Changes to TCDS: Changes to the official “Type Design” parameters (e.g., increasing Maximum Take-Off Weight, changing passenger capacity).
AD Related: The STC is being developed as an “Alternative Method of Compliance” (AMOC) to an Airworthiness Directive (AD).
Special Emphasis Items (SEI): Specific technologies listed in the TIP that EASA always wants to see (e.g., Composite fuselage repairs, certain Fly-by-wire software).

Conclusion: If the FAA STC avoids these 7 triggers, it is considered “Basic”. EASA accepts the FAA’s compliance findings 100%.

“Reciprocal Acceptance” (Tier 1: Zero Involvement)

In specific cases, EASA does not even require an application for validation. The FAA approval is valid “as is” in Europe.

Minor Changes: If the FAA classifies a change as “Minor” (and it doesn’t involve noise/emissions), EASA automatically accepts it. No application to EASA is needed.
TSO Appliances: Under recent agreements, a TSO (Technical Standard Order) article approved by the FAA is often accepted by EASA without requiring an EASA ETSO, provided it meets the reciprocal acceptance criteria.
Repair Data: Most structural repair data approved by the FAA (e.g., via Form 8110-3) is automatically accepted by EASA for use on EU-registered aircraft.

The CMT Relationships Compared

While the principles are similar, the “trust level” varies slightly between the partners.

FAA ↔ EASA (The TIP)

Status: Highly structured.
Process: Rigid “Basic vs. Non-Basic” checklists.
Friction: Sometimes, determining whether a specific tech is “Novel” can cause debate. EASA is generally stricter on “Software” and “Safety Assessment” (CS 25.1309) than the FAA.

FAA ↔ TCCA (Canada)

Status: The highest level of trust (Deep Integration).
Process: TCCA and FAA have an agreement under which almost all STCs for small aircraft (Part 23) are accepted without validation.
Distinction: Canada often accepts FAA STCs directly without issuing a Canadian STC, unlike EASA, which almost always requires an EASA STC for major changes.

FAA ↔ ANAC (Brazil)

Status: Modeled on the FAA system.
Process: Because ANAC’s regulations (RBACs) are nearly identical copies of the FAA’s (14 CFR), the “Non-Basic” list is very short.
Nuance: ANAC focuses heavily on Ethanol/Biofuel modifications (common in Brazil), which might trigger a “Novel” review if coming from the US.

Summary of Validation Principles (The “Roadmap”)

The CMT “Validation Improvement Roadmap” dictates how these authorities interact:

Sovereignty remains: Each authority issues its own certificate (except for Tier 1 acceptance).
Maximum Reliance: The Validating Authority (VA) must rely on the Certifying Authority (CA) unless a defined safety risk exists.
Work-Sharing: If EASA needs to review an FAA STC (Non-Basic), they should not review the entire document. They should review only the specific “Non-Basic” element (e.g., the battery installation, not the entire cabin interior).
Concurrent Validation: For major programs (like a new Boeing 777X), EASA and FAA work at the same time (concurrently) rather than sequentially, to speed up the final approval.