In house, MET Labs skillfully performs testing up to Level V per RTCA/DO-160 Section 22 to verify the capability of equipment installed within airborne equipment to withstand the induced effects of lightning.
There are two test types: Pin Injection and Cable Bundle. The standard covers 3 test methods: Direct, Cable Induction, and Ground Injection. Testing is performed at test levels and waveforms in line with the EUT’s expected use and aircraft installation.
Waveform selection is determined by the airframe in which the EUT is installed, i.e., all-metal, all-composite material, or a combination of the two. Environments having an all-composite airframe would be exposed to high structural voltages and lightning currents. The level of protection to exposure during a lightning event is the determining factor in test level selection.
MET’s report strictly adheres to the prescribed format:
1) Cable Configuration(s) - length, type, shielding , wiring diagram of test harness
2) Test Setups - Schematic or block diagrams with photos
3) Mode(s) of operation during cable bundle tests
4) Load(s) actual or simulated
5) All test waveforms and levels
6) Applied Transients
7) Pass/Failed Criteria
It is important to note that parts or all of DO-160 Section 22 will be incorporated in the next revision (Rev G) of MIL-STD-461. Also MIL-STD-464 will be requiring lightning testing.