Effect of Shielding and Drain Wire on Lightning-Induced Currents in Rotorcraft Cables

A strong electromagnetic field can be induced by lightning strikes on an aircraft and cause serious disturbances in electronic equipment and cables inside the aircraft. In this article, the performance of a cable protection system consisting of shielding and drain wire in an indirect lightning environment was analyzed using tests and computational simulations. The cable bundle test was conducted according to Radio Technical Commission for Aeronautics DO-160 Section 22. The shielding and drain wire performance was quantitatively evaluated by monitoring the magnitude of the induced current generated in the cable bundle. First, it was generally found that shielding was more effective than drain wire for protecting cables from lightning. In the case of the drain wire, the drain wire with high electrical conductivity showed better performance. In addition, the protection performance of the shielding and drain wire was predicted by computational simulation using the software EMA3D. Finally, the performance of the shielding and drain wires on the inner cables of the EC-155B helicopter was analyzed using computational simulations.