Static charging and its effects on avionic systems

It is pointed out that the effects of electrostatic charging first became apparent when aircraft began operation under all-weather conditions. Frictional charging of the aircraft occurred when precipitation particles struck the aircraft and deposited a charge on its surface. The charging, in turn, led to electrical discharges from the aircraft, which generated noise which interfered with the communication and navigation equipment. Techniques were developed to mitigate the undesirable effects of charging and discharging processes. Investigations related to the occurrence of static electrification are discussed, and a description is provided of interference sources and their effects on systems. Attention is given to corona discharges, streamer discharges, discharges from helicopter blades, and spark discharges.