Lightning Rod - Aircraft Protectors

Aircraft Protectors

Lightning protection for aircraft is provided by mounting devices on the aircraft structure. The protectors are provided with extensions through the structure of the aircraft's outer surface and within a static discharger. Protection systems for use in aircraft must protect critical and non-critical electronic equipment. Aircraft lightning protection provides an electrical path having a plurality of conductive segments, continuous or discontinuous, that upon exposure to a high voltage field form an ionization channel due to the system's breakdown voltage. Various lightning protection systems must reject the surge currents associated with the lightning strikes. Lightning protection means for aircraft include components which are dielectrics and metallic layers applied to the ordinarily lightning-accessible surfaces of composite structures. Various ground connection means to the layers comprises a section of wire mesh fusing the various layers to an attachment connecting the structure to an adjacent ground structure. Composite-to-metal or composite-to-composite structural joints are protected by making the interface areas conductive for transfer of lightning current.

Some aircraft lightning protection systems use a shielded cable system. These systems consist of one or more conductors enclosed by a conductive shield. The cable has both conductors of one end connected to a grounding element. This is intended to provide protection from electromagnetic interference. Such systems reduce the electromagnetically induced voltage in a shielded conductor. This is intended to provide protection against induced electromagnetic interference from lightning. This network provides a normally-high impedance which breaks down to a very low impedance in response to a momentary voltage surge electromagnetically induced in the shield. This establishes a conductive path between the shield and ground. Any surge voltage from lightning creates a current through the cable. This results in an electromagnetic field of the opposite direction, which cancels or reduces the magnitude of the electromagnetic field within the shielded cable.