RTCA DO-160 – Section 26.0 – Fire and Flammability
This section defines test conditions and procedure for Fire and Flammability resistance.
Fire and Flammability tests apply to equipment installed on fixed wing propeller driven
aircraft, fixed-wing turbojet aircraft, turbofan aircraft, prop fan aircraft, and helicopters.
These tests are applicable for equipment:
Mounted in pressurized zones
Mounted in fire zones
Mounted in non-pressurized, non fire zones
Category A: Fireproof
Intended for equipment installed in fire zone which must function during the first five minutes of fire and which must keep its safety functions for at least fifteen minutes. For fluid handling components, there shall be no leakage to support a flame after the burner has been removed (wetting or droplet that self extinguishes may be acceptable). For air handling components there shall be no leakage that may additionally feed the fire. Equipment shall remain firmly attached to the mounting. The fireproof procedure shall be applied. Test will be performed on equipment in the operating mode.
Category B: Fire Resistant
Intended for equipment installed in fire zone which must not cause a hazardous condition during five minutes of fire without structural degradation. For fluid handling components there shall be no leakage to support a flame after the burner has been removed (wetting or droplet that self extinguishes may be acceptable). For air handling components there shall be no leakage that may additionally feed the fire. In general any leakage of continued burning of the test article at the end of the five minutes would be considered a test failure unless it can be shown that there is not a significant increase in the overall fire hazard. An example of this would be if the fire extinguishing equipment is capable of extinguishing the residual flame. The fire resistant procedure shall be applied. Test will be performed on equipment in the operating mode.
Category C: Flammability
Applies to enclosures housing electronics and non-metallic material, component parts, sub-assemblies installed in pressurized or non-pressurized zones and non-fire zones. Test to be performed on equipment in a non-operating mode. The purpose of this test is to check the non-propagation of the flame in the case where ignition would appear inside or outside of the equipment. Tests will be performed on specimens of material. The flammability procedure shall be applied.
Note: If all materials used in the construction of the equipment can be shown to meet the equivalent vertical and horizontal flammability tests herein, either through composition or previous testing, this test is not required.
Testing is not necessary on enclosures housing electronic or non-metallic material if the following apply:
The enclosures is constructed of metal (metal finish that is non flammable), on all sides, and has no vent holes
The enclosures is constructed of metal (metal finish that is non flammable) on five sides and one side is constructed of glass polycarbonate (display) that has met the 12 second vertical test, and has no vent holes.