Observations on the Electrostatic Discharge Threats to Aircraft Body and to Aerospace Electronics

Abstract

Electrostatic Discharge (ESD) is a well-known threat to aerospace vehicles and microelectronic systems. This is especially so with the increased use of non-metallic, composite material for the aircraft body. Moreover, the severe lightning flashes to aircraft also commence with ESD on the aircraft body. The ESD results in the initiation of positive leaders that grow towards the thundercloud from one part of the aircraft. Moreover, a negative leader is launched towards the ground or another cloud. In this paper, we discuss the induced electric charges due to the vertical electric field component of the thundercloud charge center. Further, the electric currents induced on the surface of the aircraft body or equipment by the horizontal component of the thundercloud generated electric field is examined. From the electrostatic fields computed prior to the initiation of corona or the initial leader, we show that in addition to the most commonly identified part of the aircraft from which leaders are initiated, namely the radome, the main wing tips, the curved surface of the mid-wing and the stabilizer tips experience highly enhanced electric fields. These electric field enhancements may also lead to the generation of electric breakdown.