The Impact of the Total Lightning Environment on Aircraft Flight Control Systems

Much of the concern over lightning induced transients in critical aircraft flight control systems has centered on the return stroke cur­ rent aspect o f lightning. The very high peak currents associated with lightning (up to 200,000 amps) and the rapidly changing magnetic fields would appear to pose the most significant threat to electronic systems. However, recently reported flight data coupled with new in­ formation from laboratory tests indicate that other aspects o f the lightning flash, such as E-field changes and radiated RF, may pose as much o f a threat as the high peak currents for m odem , well-designed systems. This paper proposes a Total Lightning Threat Scenario which identifies specific aspects of a lightning strike which may impact avionics design and performance and relates them to observed labora­ tory and flight test data.