An Appendix F flammability test house plays a key role in supporting EASA certification programs, and growing industry demand is encouraging many organisations to establish their own facilities. However, creating a test house capable of performing EASA CS-25 Appendix F flammability testing is not a simple “certification” process, as EASA does not directly approve independent laboratories.
Instead, recognition comes through demonstrating technical competence, achieving ISO/IEC 17025 accreditation, and undergoing qualification by EASA Design Organisation Approval (DOA) holders. Below is an overview of the essential steps to becoming a recognised and trusted CS-25 Appendix F test house.
Understanding the Certification Landscape: Who Actually Certifies a Test Facility?
Unlike production or design organisations, independent test houses are not directly approved or certified by EASA as standalone entities.
In the EASA system, DOA holders (aircraft manufacturers, design companies, STC holders) are ultimately responsible for showing compliance with CS-25 requirements. These DOA holders may outsource testing to external laboratories. Before using an external lab, they must qualify, audit, and accept the test facility as part of their approved design assurance system.
This means the key to becoming an accepted CS-25 Appendix F test house lies in two areas:
• Technical competence and ISO/IEC 17025 accreditation
• Formal qualification by DOA holders who rely on your test results for certification programs
1. Start with a Deep Understanding of CS-25 Appendix F
EASA CS-25 Appendix F contains the flammability test requirements that support compliance with CS 25.853, 25.855, and 25.856. These tests evaluate flame behaviour, heat release, smoke generation, and burn-through resistance of aircraft interior materials.
Appendix F is divided into several parts, including:
• Part I: Vertical, horizontal, and 45-degree Bunsen burner tests
• Part II: Oil burner test for seat cushions
• Part III: Cargo compartment liner burn-through resistance
• Part IV: Heat release rate (OSU test)
• Part V: Smoke emission (Smoke Density Chamber)
• Part VI & VII: Flammability testing for thermal/acoustic insulation
To operate as a credible test house, you must ensure that the correct equipment is installed, maintained, and calibrated; staff are fully trained; and all procedures strictly follow Appendix F and supporting documents such as the FAA Fire Test Handbook.
2. Build a Robust Quality System – ISO/IEC 17025 Accreditation
While EASA does not directly approve test houses, ISO/IEC 17025 accreditation is the internationally recognised benchmark of technical competence for testing laboratories.
To achieve accreditation, you must demonstrate documented and controlled procedures, trained and qualified personnel, calibrated and traceable equipment, and technical capability for each specific Appendix F test method. Your Scope of Accreditation should explicitly list methods such as the vertical burn test, OSU heat release rate, smoke density test, seat cushion oil burner test, and cargo liner burn-through test.
This accreditation is typically the minimum requirement for any DOA holder to consider accepting your facility.
3. Qualification and Acceptance by Design Organisations (DOA Holders)
This is the most decisive step. Since DOA holders are responsible for compliance, your facility must be qualified according to their internal procedures.
A DOA qualification process usually includes submitting your quality documentation (Quality Manual, ISO/IEC 17025 certificate, test procedures, calibration data), undergoing a technical audit by the DOA holder, and demonstrating that your equipment, staff, and procedures meet Appendix F standards. Ongoing monitoring may include periodic audits and requalification whenever major changes occur.
Once accepted by a DOA holder, your test results become valid inputs for certification projects because they fall under the DOA’s approved design assurance system.
4. EASA Recognition: Indirect Certification
Although EASA does not issue direct approval to flammability test houses, your laboratory becomes indirectly recognised through the DOA qualification process. EASA accepts your test data because it is submitted through an EASA-approved DOA using an accepted facility.
This places your test house within the formal EASA certification ecosystem and positions you to support TC, STC, and major modification programs.
Summary: Your Roadmap to Becoming a CS-25 Appendix F Test House
To establish a reliable and recognised CS-25 Appendix F flammability test facility, focus on these core actions:
- Master the technical requirements of Appendix F
- Achieve ISO/IEC 17025 accreditation for relevant test methods
- Build relationships with DOA holders and undergo their qualification process
- Ensure full calibration, procedural integrity, and competent staffing
By following this path, your test house can become a trusted partner for aircraft interior material testing and support compliance with EASA’s stringent flammability standards.
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AppendixF, Appendix F, OSU test, Test House, AerospaceEngineering, AircraftCertification, TestingLaboratory, ISO17025, FlammabilityTesting, EASA, AviationCompliance, AviationSafety, STC holder, DOA holders, SAS blogs, DOA, CS25
