Like many other industrial fields, the aerospace industry is experiencing deep technical and technological changes. These changes are mainly directed towards the use at a large scale of composite materials and generalization of active avionics to deal with all aircraft functions, including those which are critical for the flights. This development, which improves the aircraft performance and increases its operational range, can only be accepted at the cost of a perfect control of flight safety, for all encountered environmental conditions. In the meantime, susceptibility of today's aircraft to lightning direct and indirect effects has noticeably increased. Three main reasons are responsible for this situation: (1) The low or even the absence of conductivity of composite materials (carbon, kevlar). (2) The increased vulnerability of microelectronic components to voltage or energy pulses, and (3) The critical role of electronics to insure the aircraft vital functions (fly by wire, engine control, etc ...). Thus, the aircraft manufacturer has to cope with new problems in the field of protection, requiring solution to restore a balance which seemed temporarily compromised. (France).