Research Airborne HF Communication System Lightning Indirect Protection Based On Airworthiness

With electronic technology development, more and more electronic equipments are installed on the modern aircraft. If without aircraft lightning protection, the functioning airborne equipment may experience upset or component damage by electromagnetic impulse of lightning. So the aviation industry pay more attention to aircraft indirect effect of lightning.Airborne high frequency(HF) radio communication system is one of the most important communication system on the aircraft, and the receiver & transmitter equipment are the core of the system. At last be sure that the receiver and transmitter equipment could withstand the induced effect of lightning.This paper briefly introduce the form and category of the lightning, but mostly research the B-747 aircraft lightning indirect effect and airborne HF communication system equipment lightning protection. Based on the three elements of electromagnetic compatibility, the interactive lightning and aircraft was studied and the effectiveness of lightning indirect protection of airborne HF communication system was verified by the the simulation data of EMA3 D software. On the one hand, study the actual transient level appear on the equipment interface and wiring of HF communication system result from the electromagnetic field induced by lightning around the aircraft which will couple into the aircraft by apertures(windows and doors etc.) or the structure IR voltages because lightning current flowing airframe from different interfere sources and transfer ways. On the other hand, based on the shield and ground protection designs, the effectiveness of the airborne HF communication system lightning indirect effect protection was verified and the simulation method of this paper could be applicable to the airworthiness certification equipment of HF communication system. At last, support the airworthiness certification of the large aerotransport lightning indirect effect protection.