Fire/smoke regulation in the aircraft field is global and has existed for several years. This regulation is international and uniform.
There are 2 standards which are, in practice, equivalent:
The CS-25 « Certification Specifications for Large Aeroplanes » features a complete list of requirements
|Part||Details||Kind of test|
|I||fire Test criteria and procedures for showing compliance with CS 25.853 or 25.855||Bunsen burner|
|II||Flammability of seat cushions acc. to 25.853(b)||Oil burner|
|III||Resistance to flame penetration of cargo lining||Oil burner|
|IV||Heat Release Rate from cabin materials exposed to radiant heat and flame||OSU chamber
|V||Smoke emission characteristics of cabin materials exposed to radiant heat and flame||NBS chamber
|VI*||Resistance to Flame Propagation of insulation materials||Radiant panel|
|VII*||Resistance to Flame Penetration of insulation materials||Oil burner|
Consequently, France directly uses the FAR 25 / CS 25 parts 23, 27 and 29 corresponding to the fire/smoke requirements. When the FAR / JAR is not complete, industrial test methods can be required. Thus, there are two others principal standards from BOEING and AIRBUS, respectively the « BOEING SAFETY STANDARD » or BSS and the « AIRBUS INDUSTRIE TEST METHOD » or AITM. These last ones are described in a framework document: the ABD0031.
CREPIM is well equipped to realize principal tests according to this reference. The most majority of our tests in this area are realized under COFRAC accreditation.
The tests which can be led in the CREPIM are the following ones:
Allumability test – 60 s with a vertical burner – (FAR 25.853 (a) / BSS 7230 F1)
Allumability test – 12 s with a vertical burner – (FAR 25.853 (b) / BSS 7230 F2)
In this fire test, a flame is applied to the sample, which is in a vertical position, to assess the fire behavior of the material for a flame application time of 12 or 60 seconds. The recording parameters are:
30 s with a burner at 45° – (FAR 25.855 (a) / BSS 7230 F5)
This fire test consists in the application of a flame on a sample at 45° to assess the fire behaviour of the material for a flame application time of 30 seconds.
The recording parameters are:
Propagation test – Speed < 64 mm/min (2,5 inches/min) – (FAR 25.853 (b-2) / BSS 7230 F3)
Propagation test – Speed < 102 mm/min (4 inches/min) – (FAR 25.853 (b-3) / BSS 7230 F4)
The aim of this fire test is to apply a flame to a sample in a horizontal position to assess the flame propagation speed on the material. Two speed criteria exist according to the final use of the product in the aircraft binnacle.
The propagation speed is measured thanks to 2 landmarks on the sample.
This fire test allows the simultaneous measurement of the release smoke quantity dispersed in a fixed air volume by a material under a radiant heat source and the toxicity of the gaseous effluents
The opacity is recorded by the transmission of a light beam inside the chamber throughout the period of test and the relevant parameter is a maximal specific density or Dm. The maximum tolerated Dm depends on the final use of the product and can varies from 100 to 200.
The smoke density is measured thanks to Fourrier transformed infra-red (FTIR) with a gas cell. The sample is directly taken inside the smoke chamber when the measured density is maximal. The measured gases are: HF, HCl, HCN, SO2/H2S, NO/NO2 and CO.
How to translate FAR 25 853 requirements to key plane makers requirements
|Test description - Appendix F||FAR Appendix F||Airbus||Boeing|
|Combustion toxicity||N/A||AITM 3.0005||BSS 7239|
|Rate of Heat Release (OSU)||Part IV||AITM 2.0006||BSS 7322|
|Smoke density||Part V||AITM 2.0007 A||BSS 7238|
|Vertical flammability (60 s flame application)||Part I (a)(1)(i)||AITM 2.0002 A||BSS 7230 F1|
|Horizontal flammability||Part I (a)(1)(iv)
Part I (1)(1)(iv)
|AITM 2.0003||BSS 7230 F3
BSS 7230 F4
|Vertical flammability (12 s flame application)||Part I (a)(1)(ii)||AITM 2.0002 B||BSS 7230 F2|