Lightning Indirect Effects
Section 10: Environmental Qualification (DO-160)
Definition
The transient voltages and currents induced in aircraft wiring and equipment by the electromagnetic fields and resistive voltage drops produced when lightning current flows through the aircraft structure. Indirect effects can cause upset, damage, or erroneous operation of avionics and electrical systems. DO-160 Section 22 defines equipment-level tests for lightning indirect effects (pin injection testing and cable bundle testing).
Where This Shows Up
Lightning indirect effects testing at the equipment level uses standardized transient waveforms injected onto equipment pins or cable bundles to simulate the voltages and currents induced by lightning strikes. The test waveforms (Waveform Set 1 through 5 in DO-160 Section 22) represent different coupling mechanisms. The severity levels are determined by the aircraft-level lightning indirect effects analysis, which considers the aircraft structure material (composite vs. metallic), wiring routing, shielding, and the equipment's functional criticality. Equipment performing critical or essential functions must continue to operate correctly during and after lightning-induced transients.
Primary Sources
Section 22 (Lightning Indirect Effects) — defines pin injection and cable bundle test methods, waveforms, and severity levels.
Aircraft Lightning Test Methods — provides aircraft-level lightning test methods that support the derivation of equipment-level test levels.
Aircraft Lightning Direct Effects Certification — European guidance on the lightning certification process.
Related Terms
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