What It Looks Like

Your first encounter with aircraft static wicks may be when you accidentally collide with one while conducting a preflight inspection. After all, those thin, wispy wires protruding off the trailing edge of wings and tail can be difficult to spot when you're concentrating so hard on inspecting control surface hinges and the like. But though they may seem to be nothing more than a nuisance on the ground, static wicks can perform an important function in the air.

Electrostatic charges can accumulate on an airplane as it flies through precipitation, ice crystals, dust, sand, snow, and even in clear air below an electrically charged cloud layer. The electrostatic charge can build on a metal airframe, on fiberglass components exposed to the slipstream, on isolated pieces of metal, and even on some highly polished painted surfaces.

An electrostatic charge buildup can cause radio frequency (RF) noise that may interfere with VHF communications and navigation receivers, ADF, and other avionics. RF noise is heard as a loud background hissing when transmitting or listening on the communications receiver. If the static discharge is strong enough, it may even desensitize an avionics receiver to the point where it will not function.

Static wicks are designed to bleed electrostatic charge off into the slipstream before it can build to the point of interfering with avionics. Generally, the faster the airplane the greater the potential for electrostatic buildup. However, even light general aviation aircraft are subject to the phenomenon. If the airplane you fly isn't fitted with static wicks, take a walk around the ramp-you'll see plenty of aircraft that are.

There is a science to the number and placement of static wicks. That's a job for the avionics shop. What you should be concerned with is that the wicks attached to the airplane you fly are in good shape, not broken or excessively frayed. This is especially important if you are an instrument-rated pilot and will be flying in visible moisture.

If you discover problems with static wicks during your preflight inspection, report them to the owner or operator of the aircraft. And don't forget to avoid walking into them during your preflight.