Susceptibility of avionics to lightning indirect effects

The ways that lightning currents may flow in an airframe and basic mechanisms whereby these currents may induce transient voltages and currents in typical aircraft electrical circuits are described. Examples of induced voltages and currents measured during simulated lightning tests are presented and significant aspects are discussed, together with estimates of the ranges of induced voltages to be expected in typical circuits. Examples of the magnetic fields that are responsible for some of these induced effects are also presented. A discussion of the basic damage effects that lightning induced voltages may have on typical solid state electronic components is included.