Resonate Testing supports aerospace manufacturers through development, qualification and certification evidence using ISO 2685, FAA AC 20-135 and customer-defined fire protection requirements for UK, Ireland and international programmes.
ISO 2685 :Title Aircraft — Environmental test procedure for airborne equipment — Resistance to fire in designated fire zones, defines fire resistance testing exposes aerospace components to severe flame conditions and may be used as a means of compliance for OEM and equipment suppliers to demonstrate performance for equipment installed in aircraft fire zones.
Fire resistance: Verifies whether the test item can withstand the required fire exposure without unacceptable loss of integrity. There are two categories with unique roles- Fire Resistance ~ 5 Minute exposure and Fire Proof ~15 minutes exposure.
Calibrated flame exposure: Uses kerosene or oil burner systems to generate conditions aligned with aerospace fire protection requirements.
Typical temperature: ISO 2685 programmes commonly involve flame exposure around 1100°C / 2012°F for the specified duration.
Component focus: Supports nacelle structures, firewalls, hoses, fluid systems, thermal protection materials and propulsion-related equipment.
Evidence generation: Produces observations, instrumentation data and reporting to support development, qualification or certification activity.
Resonate supports aircraft fire testing programmes for aerospace components, nacelles and fire-zone hardware. ISO 2685 testing focuses on proving that hardware can resist severe flame exposure while maintaining containment, structural integrity and required function under representative installation conditions.
FAA AC 20-135 fire protection guidance
RTCA DO-160 Section 26
SAE AS6826 fire test methods
Customer certification requirements
AC20-135 Aircraft Fire Testing
Ready to plan an ISO 2685 fire testing campaign? Send your requirement, drawings, installation assumptions or certification plan
for engineer review and receive guidance on fireproof or fire-resistant classification, setup, instrumentation and evidence
requirements.
Fire resistance programmes often need early review of the component design, applicable fire zone, operating condition and pass/fail evidence required by the customer or certification route.
Share your component description, drawings, material details, pressure or airflow requirements, thermocouple locations, acceptance criteria and target standard. Resonate Testing can review burner setup, fixturing, instrumentation and reporting expectations before quotation.
ISO 2685 fire resistance and burn-through testing
FAA AC 20-135 and customer requirement review
Nacelle, firewall, hose and propulsion component assessment
Fluid pressure, airflow, vibration and temperature monitoring options
Development, qualification and certification support
Aerospace fire testing is driven by the installed location, certification basis and the role of the component in a designated fire zone. Requirements may reference ISO 2685, FAA AC 20-135, CS/FAR expectations or customer-specific procedures.
The objective is not simply to expose a part to flame. The objective is to generate traceable evidence that the component maintains the required level of fire resistance, integrity or containment during and after the specified exposure.
Before testing begins, the programme should confirm burner calibration, flame temperature, exposure duration, mounting orientation, service loads, fluid pressure, airflow, vibration, instrumentation and acceptance criteria.
Early standards review helps reduce rework and ensures the final test evidence aligns with the certification or customer approval route.
| 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. |
Testing performed to ISO 2685 is intended to evaluate how aerospace components behave when exposed to severe flame conditions representative of aircraft fire-zone events. Typical objectives include assessing fire resistance, burn-through behaviour, leakage, structural integrity and continued containment during the specified exposure.
Test planning is normally based on the specific component and certification requirement, including flame temperature, exposure duration, mounting orientation, fluid pressure, airflow, vibration, instrumentation, inspection points and reporting expectations. Applicability should be confirmed for the exact hardware, installation and programme requirements before testing begins.
In ISO 2685 testing, the component’s condition during and after flame exposure is central to the evidence package. Leakage, burn-through, loss of containment, visible degradation and changes at seals or joints should be considered when defining acceptance criteria.
Risk should be reviewed early if the item includes pressurised fluids, composite materials, insulation, coatings, seals, bonded joints, batteries or stored-energy features. Instrumentation, photographs, witness inspection and safe depressurisation steps should be agreed before the test is quoted or committed.
Aerospace components may need more than a standalone flame exposure. Coordinating fire resistance testing with vibration loading, fluid pressure, airflow or related environmental tests helps align fixtures, instrumentation and documentation across the full programme.
For projects that also need mechanical or environmental testing, review the related services before finalising the campaign sequence and evidence package.
Outputs are agreed before the test so the evidence matches the programme need. A typical package may include:
Recorded flame temperature, component temperature, pressure and agreed instrumentation data
Evidence of achieved burner conditions, exposure duration and agreed operating loads
Observations from setup, test execution and post-test review
Photographic evidence where agreed
Integrity, leakage, burn-through or containment observations where included in the plan
An agreed test report or data pack aligned to the quotation scope
Resonate Testing provides engineer-led aerospace fire resistance testing for components used in aircraft engine, nacelle and designated fire-zone applications. Programmes can be planned against ISO 2685, FAA AC 20-135 and customer-defined fire protection requirements.
The laboratory supports development, validation, qualification and certification evidence for metallic and composite structures, firewalls, hoses, fluid systems, propulsion components, battery enclosures and thermal protection materials.
Successful ISO 2685 testing requires more than applying a flame. Test planning may include burner calibration, flame temperature confirmation, exposure duration, thermocouple placement, pressure monitoring, leakage checks, visual observations and post-test integrity assessment.
Where the requirement demands it, Resonate can introduce operational stresses during fire exposure, including vibration loading, bleed air or airflow simulation and fluid pressure application. This helps evaluate components under conditions closer to in-service operation.
Early engagement helps identify fixture needs, safe operating limits, instrumentation access and practical risks before the test campaign starts.
Fire resistance describes the component’s ability to withstand the specified flame exposure while maintaining the required integrity, containment or function defined by the test plan.
Burn-through is a loss of material or barrier integrity that allows flame, hot gases or leakage to pass through the component beyond the allowed acceptance criteria.
Integrity may be assessed through visual inspection, leakage checks, pressure behaviour, photographs, temperature data and post-test observations agreed before the test.
Fluid pressure can represent in-service operating conditions for hoses, ducts, pipes, valves or fluid system components during fire exposure.
Vibration loading can represent engine or aircraft operating conditions and may reveal failure modes that a static flame exposure would not show.
Repeatedly moving the test item between defined hot and cold temperatures to reveal issues such as expansion, contraction, fatigue or changing operating conditions.
Plan: Review the standard, certification basis, fire-zone requirement, acceptance criteria and safety considerations.
Prepare: Confirm fixtures, burner setup, fluid pressure, airflow, vibration and instrumentation needs.
Mount and instrument: Install the component, connect agreed channels and verify safe operation before exposure.
Calibrate and expose: Confirm burner conditions, then run the specified flame exposure at the agreed orientation and duration.
Monitor: Record temperatures, pressures, visual observations and any functional or leakage checks required by the plan.
Review and report: Assess integrity, burn-through, observations, photographs, plots and agreed outputs.
Component drawings, installation orientation and fire-zone context
Target standard, customer specification and acceptance criteria
Required exposure duration, burner orientation and flame condition
Fluid type, operating pressure, leakage criteria and safety limits
Airflow, bleed air or vibration requirements during fire exposure
Thermocouple, pressure, visual or customer instrumentation requirements
Material details, coatings, seals, insulation and containment features
Hazardous material, stored energy, pressurised system and fuel safety information
Pre-test inspection, witness, photography and post-test assessment needs
Reporting, photographic evidence and witness requirements
Outputs are agreed before the test so the evidence matches the programme need. A typical package may include:
Recorded flame temperature, component temperature, pressure and agreed instrumentation data
Evidence of achieved burner conditions, exposure duration and agreed operating loads
Observations from setup, test execution and post-test review
Photographic evidence where agreed
Integrity, leakage, burn-through or containment observations where included in the plan
An agreed test report or data pack aligned to the quotation scope
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