Static Discharger (Lightning Protection)

The aluminium used on most commercial aircraft conducts electricity and allows lightning to pass across its skin. The current usually exits the aircraft at the tail. Image: nzherald.co.nz

Static dischargers, also known as static wicks, are devices that dissipate static electricity buildup on aircraft, reducing radio interference and, in some cases, serving as a lightning conductor to protect the airframe. Their history dates back to the early days of aviation, with early designs focusing on improving radio communication and, later, on lightning protection.

What Static Dischargers Do

Static Electricity Dissipation: Aircraft flying through the air can accumulate static electricity due to friction with the atmosphere. This static buildup can cause radio interference, making communication and navigation challenging. Static dischargers, with their high electrical resistance and sharp points, effectively dissipate this static electricity into the air, preventing interference.

Lightning Protection: While not designed as primary lightning arresters, static dischargers can help divert lightning strikes away from critical parts of the aircraft. By concentrating electrical charge around their tips, they can channel lightning current through a safe path, minimizing potential damage to the airframe.

Location: Static dischargers are typically installed on the trailing edges of wings, tail surfaces, and other protruding areas of the aircraft.

Types

Null-Strike static dischargers feature "Strikeguard", finely deposited aluminum particles epoxied on the surface of the discharger with an extremely strong adhesive, which is used as a means of diverting a lightning strike to the tip of the discharger rather than the edge of a wing in order to minimize damage to the airframe.

History of Static Dischargers

Early Aviation: As aviation technology advanced, the need to address static electricity interference became apparent. Early static dischargers were simple wire-like structures designed to release static charges into the atmosphere.

Development and Refinement: Over time, static discharger designs evolved to improve their effectiveness, incorporating materials with higher electrical resistance and sharper points.

Modern Designs: Modern static dischargers are more sophisticated, with some designs incorporating lightning protection capabilities in addition to static electricity dissipation.