Aero-Mach TCO

What is a Static Discharger?

Static dischargers are mounted along the trailing edges of an aircraft’s wings and tail and are designed to safely dissipate static electricity in flight. As an aircraft moves through the atmosphere, it naturally builds an electrical charge from friction and environmental conditions.

If that charge is not managed, it will discharge from random points across the airframe, creating unstable electrical activity that can show up as radio interference or reduced communication clarity. Sometimes, it even appears as a blue glow called “St Elmo’s Fire”.

How Do Static Dischargers Work?

As a charge builds during flight, the electrical field naturally becomes strongest at sharp points. Static dischargers take advantage of this and concentrate the field at their tips, which allows the surrounding air to ionize and begin shedding charge as soon as that threshold is reached.

This process – called “corona discharge” – creates a steady, continuous flow of energy off the aircraft rather than intermittent bursts from random points like antennas or edges. As a result, radio and navigation performance is improved, especially in precipitation or electrically active environments.

In addition, aircraft static wick placement along the trailing edges aligns them with airflow and promotes efficient discharge with minimal aerodynamic impact.

What About Static Wick Testing and Maintenance?

Static wicks only work when they’re intact and properly bonded to the aircraft. Inspection typically begins with a visual check. Each wick should be present, securely attached, and free of obvious damage. The fibrous tip should not be burned, heavily frayed, or missing, and the base should be tight with no signs of corrosion or looseness. Missing or damaged wicks are one of the most common causes of in-flight radio static.

Beyond visual condition, electrical continuity is important. A static wick must have a reliable conductive path to the airframe to do its job. Using a multimeter, maintenance personnel can verify continuity between the wick and the aircraft structure. High resistance or an open circuit indicates poor bonding, contamination, or internal failure of the wick, any of which can prevent effective discharge.

Inspection should also consider overall coverage. Wicks are installed in specific locations along trailing edges to create a balanced discharge pattern. If one or more are missing, the system becomes less effective, and electro static discharge may shift to less ideal points on the aircraft.

As a practical rule, if a wick is damaged, loose, or missing, it should be replaced – not repaired – to restore proper performance and maintain reliable avionics operation.