Investigation of the success of shielding termination against the indirect effects of lightning on aircraft

Lightning is a natural phenomenon where high voltages and currents suddenly discharge. It can be caused by clouds themselves, clouds between them, or clouds near the earth. Aircraft are also at risk of being struck by lightning and there is currently no way to prevent this from happening. Instead, efforts are being made to protect by reducing the effects of lightning. Metal structures in aircraft form a Faraday cage which helps in preventing lightning currents from entering the aircraft. However, composite structures, which are becoming more prevalent in the aviation sector, are less efficient in doing so compared to metals. Additionally, openings such as windows in the aircraft can break the Faraday cage and allow strong electromagnetic fields to penetrate. Hence, all equipment used on board the aircraft must be adequately qualified and lightning-proof. The most popular technique used to reduce the indirect effects of lightning on electronics is cable shielding. In this study, various shield termination techniques against the indirect effect of lightning were examined both by experimental methods and by simulation studies in the EMA3D program, and it was found that the use of 360˚ back shell termination technique was very effective by providing about 3 dB of protection. The results obtained from the experiments are compared with simulation results and previous studies and it has been observed that the obtained results are consistent with each other.