If you ever look at the trailing edge of an airplane’s wings, you may notice an array of small rod-like devices attached to it. These aren’t flight control surfaces. Rather, these unusual-looking appendages are static wicks.
What Are Static Wicks?
Static wicks are devices that safely discharge static electricity. Without them, airplanes would experience communication disruptions or electrical malfunctions during flight.
Most static wicks consist of small metal rods. They are found on the trailing edge of an airplane’s wings where they stick out and point backwards. The purpose of static wicks is to dissipate static electricity into the surrounding atmosphere.
How Static Electricity Occurs in Airplanes
Static electricity can build up on airplanes. As they move through the air, airplanes generate friction between the hull and the atmosphere. This friction, if left unchecked, leads to static electricity.
The amount of friction an airplane generates will vary depending on the type of atmosphere through which it’s flying. If the skies are clear, it will generate a minimal amount of friction. If it’s raining, snowing or cloudy, on the other hand, it will generate more friction. And the more friction an airplane generates, the more static electricity it will produce.
Lighting strikes can also lead to static electricity. Modern airplanes are designed to handle lightning strikes, but direct or indirect strikes can still cause static electricity.
The Impact of Static Electricity
Static electricity can interfere with an airplane’s avionics and communications. As the hull becomes statically charged, the airplane may experience disruptions when sending and receiving radio transmissions. This can make it difficult for pilots to safely navigate, as they will struggle to communicate with Air Traffic Control (ATC).
How Static Wicks Work
Fortunately, most airplanes are equipped with static wicks to deal with static electricity. They are found on places where friction is most problematic, such as the trailing edge of the wings.
Static wicks are connected to the airplane’s grounding system, thereby providing a path for static electricity to safely dissipate. The wicks will absorb static electricity during flight, at which point the electrical charge will travel through the airplane’s grounding system before dissipating.
It’s important to note that static wicks can wear down over time. Regular exposure to severe weather like rain, snow and high winds can erode them. Therefore, airlines must inspect and replace static wicks regularly to ensure they work as intended.
