Lightning Indirect Effects on Helicopter: Numerical Simulation and Experiment Validation

When lightning strikes an aircraft, the electromagnetic (EM) field penetrates inside the aircraft, and induces currents and voltages on the onboard cables, resulting in the risk of equipment failure, which is a serious safety hazard to the flight safety. With the wide use of low-conductivity composite materials in aircraft manufacturing, the EM shielding effectiveness of the aircraft is weakened. As for the helicopter, the proportion of windows and doors is relatively larger than the fixed-wing aircraft, thus the EM shielding effectiveness is much weaker. Proper lightning protection design must be validated to eliminate the risk of electrical and electronic equipment failure. This paper describes the lightning indirect effects related to the modeling and simulation process of the composite UH-60 helicopter. The external and internal EM field environment together with the induced currents and voltages on cables are discussed. Moreover, in order to validate the simulation, an iron helicopter model was tested and the comparison between simulated and measured waveforms was carried out.