The Direct Effects of Lightning on Aircraft

Protection of aircraft against the physical-damage effects and fuel-vapor ignition hazards of lightning has long been a concern of aircraft designers. These hazards are now referred to as the "direct effects" and include the damage that may occur at the lightning-attachment spots on the aircraft, as well as the possibility of electrical sparking that may occur within fuel tanks. As aircraft design have changed, new methods to protect the aircraft against these effects have had to be developed. This need is expecially true with respect to structures made of fiber-reinforced plastics and other non metallic materials, which are often more vulnerable to damage than conventional aluminum structures. In this paper, we review the potential hazards, protection methods and some of the test techniques available for design verification.