Explosive Atmospheres Testing for Aviation

The tests of section 9 are performed to demonstrate the ability of equipment to operate in fuel-air explosive atmospheres without causing ignition. The tests apply to all equipment designed for use in the vicinity of fuel-air explosive atmospheres associated with aircraft.

• Testing in the UK
• Elevated ambient temperatures up to 70ºC
• Standard chamber for equipment <0.5m³
• Special chambers for larger equipment >0.5m³

TRaC can test most sizes of equipment and we specialise in testing larger items. Please contact us for more information on special tests.

The explosive atmosphere tests are generally conservative tests. If the test item does not ignite the test fuel-air mixture, there is a low probability that it will ignite prevailing fuel vapour mixtures in service. Conversely, the ignition of the test fuel-air mixture by the test item does not mean that it will always ignite fuel vapours that occur in actual use.

There are three types of tests within section 9 of RTCA DO-160F. These tests apply to specific categories of equipment (A, E and H). The categories are suitable for use in three environments (I, II and III). The environments determine the severity of the tests.

• Category A test – Tests the effect of an explosion of an atmosphere within an equipment and the ability of the design to prevent this explosion spreading outside of the enclosure. Tests conducted under normal and fault conditions.
• Category E test – This test ensures that temperatures and sparking parts do not ignite an atmosphere under normal conditions.
• Category H test – This is a test to prove that there are no high temperatures that could cause an explosion under normal operating conditions.

The tests of section 9 of RTCA DO-160F are usually applied after completion of environmental stress tests (detailed elsewhere in RTCA DO-160F). This ensures that seals and enclosures are representative of service use. The test is normally conducted at highest operating service ambient conditions. The effect of altitude is not taken into account during these tests and hence they are normally performed at ground ambient pressure.