AS6826-aligned technical review and test planning for powerplant, APU, firewall, nacelle and propulsion-system fire-protection evidence.
Resonate can review SAE AS6826 fire-testing requirements and advise on a technically suitable approach, subject to scope confirmation. Programmes consider the installation, fluids, loading, vibration, functional behaviour and reporting route before the test plan is agreed.
SAE AS6826, Powerplant Fire Test Standards, provides guidance for demonstrating compliance with powerplant fire-protection requirements by fire test. Issued in April 2025, it covers methods and rationale for testing powerplant and Auxiliary Power Unit components and installations.
The standard supplements FAA AC 20-135 Change 1 and was prepared by the SAE A-22 Fire Protection and Flammability Testing Committee. It harmonises flame temperature, heat transfer, setup, calibration, instrumentation, boundary conditions and component-specific pass/fail criteria.
Planning an AS6826 programme? Send the compliance plan, drawings, operating conditions, fire-intended functions and acceptance criteria for engineer review.
AS6826 programmes require early review of the test article, representative installation, operating environment, fire-intended functions and certification route.
Share the compliance plan, drawings, material and interface details, operating conditions, monitoring requirements and acceptance criteria. Resonate can review the proposed setup and evidence package before quotation.
AS6826-aligned technical review and test planning
FAA AC 20-135 Change 1 and compliance-plan review
Powerplant, APU, nacelle, firewall, hose and control assessment
Pressure, flow, vibration, load and functional monitoring review
Calibration, test execution and certification-evidence planning
AS6826 defines a Standard Flame of at least 2000°F / 1093°C with a minimum heat-transfer rate of 4500 Btu/h / 1319 W. The burner must meet the standard’s requirements and retain its calibrated physical, fuel-flow and airflow settings through the test and post-test validation.
Temperature calibration uses a seven-thermocouple rake. All seven channels are recorded for at least three minutes at 0.5 Hz or faster; each channel’s average must meet the specified temperature band and the inner-five rake average must be at least 2000°F / 1093°C.
Heat transfer is measured with the Appendix A continuously water-cooled copper-tube apparatus. Pre-test calibration must demonstrate at least 4500 Btu/h / 1319 W, followed by post-test validation against the applicable threshold.
| Reference | Typical relevance |
|---|---|
| ISO 2685 | Fire resistance test method for aircraft components exposed to designated fire-zone conditions. |
| FAA AC 20-135 | Guidance for demonstrating fire protection performance for aircraft materials and components. |
| CS/FAR fire-zone requirements | Certification context for components installed in engine, nacelle and other fire-zone areas. |
| Customer specifications | Component-specific acceptance criteria, operating conditions, instrumentation and reporting expectations. |
| Reference | Typical relevance |
|---|---|
| Standard | SAE AS6826, Powerplant Fire Test Standards, issued April 2025. |
| Standard flame | At least 2000°F / 1093°C and 4500 Btu/h / 1319 W heat transfer. |
| Fire-resistant | At least five minutes of flame exposure, with required functional and post-exposure monitoring. |
| Fireproof | 15 minutes of continuous flame exposure, with applicable boundary conditions and monitoring. |
AS6826 requires the test to represent the component’s operating environment and intended function. Depending on the hardware, the plan may address vibration, load, differential pressure, backside airflow, commanded function, fluid pressure and flow, fluid temperature, reservoir quantity, rotational speed and test fluid.
Burner orientation is normally horizontal or vertical and must remain consistent through calibration and testing. Angled use and unusual boundary conditions should be coordinated with the relevant Certification Authority.
Each AS6826 enquiry begins with a feasibility and requirement review. Engineers examine the compliance plan, hardware configuration, mounting, operating conditions, fire-intended functions, hazards and component-specific acceptance criteria.
Resonate supports AS6826-aligned technical review and test planning. Final scope, accreditation status and the certification route must be confirmed for the specific programme.
| Specification | Capability |
|---|---|
| Standard | SAE AS6826 — Powerplant Fire Test Standards |
| Typical Flame Temperature | At least 1093°C / 2000°F |
| Burner System | Compliant modified gun-type oil burner or other burner meeting AS6826 criteria |
| Applicable Requirements | AS6826, FAA AC 20-135 Change 1 and the approved compliance plan |
| Component Types | Powerplant and APU installations, firewalls, nacelles, controls, hoses, seals and related components |
| Combined Conditions | Vibration, load, differential pressure, airflow, fluid conditions and commanded function as applicable |
| Instrumentation | Seven-thermocouple temperature rake, heat-transfer calibration and test-specific channels |
| Assessment Focus | Component-specific burn-through, flame penetration, load, ignition, leakage and functional criteria |
| Test Planning Support | Standard review, fixture planning, burner setup, safety review, instrumentation and reporting scope |
AS6826 does not use one generic pass criterion. Depending on the test article and function, the plan may address burn-through, flame penetration, maintained load, backside ignition, residual flames, leakage or gapping, and continued fire-intended function.
Multi-function components require all relevant functions to be considered. The test plan should define the leakage-detection method, permitted residual-flame behaviour and any functional response such as valve closure or safe engine shutdown.
AS6826 addresses representative powerplant and APU hardware, including firewalls and shrouds, cowling and nacelles, controls and shutoff valves, fire seals and penetrations, extinguishing lines, hoses, tubes, fittings, wires, connectors and electronic controls.
Hardware should represent production materials, manufacturing features, installation interfaces and heat paths. The exact setup and criteria depend on the component’s location, function and compliance plan.
Plan: Review the standard, certification basis, fire-zone requirement, acceptance criteria and safety considerations.
Prepare: Confirm representative hardware, fixtures, boundary conditions, instrumentation and functional checks.
Mount and instrument: Install the component, connect agreed channels and verify safe operation before exposure.
Calibrate and expose: Verify temperature and heat transfer, then apply the flame for the required five- or 15-minute duration.
Monitor: Record temperatures, pressures, visual observations and any functional or leakage checks required by the plan.
Validate and report: Complete post-test burner validation and document criteria, deviations, photographs, data and witnesses.
Applicable standard revision, test profile or customer procedure
Product description, dimensions, mass and sample quantity
Drawings, mounting details and representative installation information
Functional monitoring and instrumentation requirements
Customer-defined acceptance criteria
Hazards, stored energy and special handling information
Required test window and witness arrangements
Photographs or previous test data where useful
Required data, photographs and report format
SAE AS6826 provides fire-test methods and rationale for demonstrating powerplant and Auxiliary Power Unit component and installation fire-protection requirements.
AS6826 originated from FAA AC 20-135 Change 1 and significantly supplements it. Project-specific compliance plans should still be coordinated with the relevant Certification Authority.
The Standard Flame is at least 2000°F / 1093°C with a minimum heat-transfer rate of 4500 Btu/h / 1319 W, calibrated using the standard’s procedures.
Yes. Heat transfer is validated after testing against the applicable threshold. A result below that threshold requires the fire test to be repeated.
Fire-resistant testing uses at least five minutes of flame exposure. Fireproof testing uses 15 minutes of continuous flame exposure, with applicable monitoring and boundary conditions.
Yes. Applicable conditions may include vibration, load, pressure, airflow, fluid conditions, rotational speed and commanded function.
Repeatedly moving the test item between defined hot and cold temperatures to reveal issues such as expansion, contraction, fatigue or changing operating conditions.
Outputs are agreed before the test so the evidence matches the programme need. A typical package may include:
Before, during and after photographs
Pre-test calibration and post-test validation data
References to test-article drawings and production type design
Boundary-condition, procedure and pass/fail statements
Results, residual-flame details, deviations and authority dispositions
Conformity package, observations and witness attendance list
Share the compliance plan, controlled requirements, product details, drawings, representative operating conditions, fire-intended functions and acceptance criteria. An engineer can review feasibility and advise on a technically suitable approach, subject to scope confirmation.
Whether you’re looking to contact us for the first time or have another testing requirement, we’d love to hear from you.
