Stunning Airplane Cockpit Window Static Discharge when Flying

Difference between Inflight Static Discharge and St. Elmo's Fire

Did you know that the airplane cockpit window occasionally gets some spectacular static discharge, which passengers never get to see?

While you are enjoying your meal in the back of the airplane, your pilots could be enjoying a beautiful “light show” from their cockpit windows.

Boeing 767 airplane inflight cockpit window static discharge video

Here’s a “ringside view” of the cockpit window static discharge spectacle so you can see this for yourself:

The video shows static discharge in the cockpit windows of a Boeing 767.

There are often plenty of highly charged thunderstorms in this area, located above the Andes Mountains on a typical “red-eye” South American summer night-flight.

Cockpit Window Static Discharge Video B767 (no sound). Video: CaptainJetson.com.

Airplane cockpit window static discharges are totally harmless

Watching this static discharge dancing across the windows of the flight deck is fun. Cockpit window static discharges are not dangerous, but the “lightning show” offers an occasional spectacular view in the cockpit indeed!

Let’s look further into this stunning show of display that pilots sometimes get to enjoy…

What causes Airplane Cockpit Window Static Discharge?

cockpit windows
Cockpit Windows of a Boeing airliner. CaptainJetson.com.
  • In simple terms, it’s caused by a large amount of static electricity buildup around the windows.
  • The buildup, in turn, causes an electrical discharge.
  • That electrical discharge then manifests as a light-show on the window surface.

Static discharge can be seen and felt in our daily lives

We have all experienced static discharge in our daily lives.

These discharges can be seen as “sparks” in a dark room, they are heard as a crackle-sound, and they come with an “electrical” smell.

Let’s say you remove your blankets from your dryer after wash and dry. You forgot to insert a dryer sheet prior to dry to avoid static cling. Now turn off the light and shake your blanket.

As the excess static discharges, you can see the harmless sparks, hear the sound of the discharge, and sometimes smell the electrical reaction.

You just experienced a static discharge, witnessing the same static reaction that pilots see on their windshields!

Now let’s look at an airplane cockpit static discharge

Static electricity builds when an airplane is flying through the sky.

The static electricity is caused by the air and *precipitation which surrounds the airplane. The air and precipitation are constantly rubbing the skin of the airplane, causing friction. The friction, in turn, creates an electrical charge, or static electricity.

*Precipitation consists of rain, snow, ice, or dust particles.

Why doesn’t static discharge show in passenger cabin windows?

Cockpit windows face the oncoming wind and surrounding particles head-on, creating a rapidly producing discharge friction effect.

Cabin windows are on the side of the airplane, causing less friction, which is not enough to produce the static discharge effect.

Static Wicks minimize the effects of static discharge

airplane static discharge wicks

static wicks on a jet

Airplane wings static discharge wicks. CaptainJetson.com.

Static dischargers, also called static wicks or static discharge wicks, are installed on the back of the wings and the tail.

The static charge is continuously eliminated with the help of the small. pointed wicks.

The wicks prevent problem-free operation of radio communications equipment and onboard navigation electronics during precipitation. This disturbance is called precipitation static, or p-static.

The static wicks are designed to discharge the static (electrical friction) buildup into the air.

The charge is discharged through the wicks because they contain sharper metal points than what is found anywhere else on the airplane.

sharp points airplane static wicks
Different designs of airplane wing static discharge wicks. CaptainJetson.com.

The wicks will not work unless they are properly bonded to the airplane. 

Every part of the airplane must have a conductive path to the dischargers. Otherwise, they would be useless. 

Although the wicks are mounted on the wings and on the tail the origins of the path are located on every door, access panel, navigation lights, antennas, cowls, control surface, and in other places.

When were airplane static wicks invented?

Military airplanes were the first to be equipped with static wicks during World War II in the 1940s.

A joint Army-Navy team, led by Dr. Ross Gunn of the U.S. Naval Research Lab came up with the discovery, then installed the static wicks on military aircraft.

Why do the windows spark if we have static wicks?

The majority of the airplane skin (metal composite) is connected to the static wicks. Metal is needed to create a bond or a connection for electrical continuity, such as the static discharge system.

The windows are made from a glass-type, and they do NOT bond or connect with the static wicks.

Therefore the precipitation static build-up on windshields is not neutralized by the static wicks.

Precipitation static is produced from things like clouds, heavy rain, and snow.

Therefore, the window precipitation static is left to discharge on its own. 

The result is that stunning cockpit window static display!

Airplane St. Elmo’s Fire

There is another phenomenon occurring in the air, which is often confused with window static discharge, because of its apparent similarity in visual presentation. However, the physics behind each phenomenon is different.

This other phenomenon is called St. Emo’s Fire.

Airplane Cockpit Static Discharge is a different phenomena than an Airplane St. Elmo’s Fire.

You can read about inflight St. Elmo’s Fire here.

Questions or comments? Please contact us here.

Featured Image, video & other pictures: CaptainJetson.com

This article was updated on July 23, 2020.

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What causes airplane cockpit window static electricity?

Cockpit window static electricity happens when there is an unbalance of electric charges on the surface of the window. Heavy cockpit window static electricity activity sometimes appear like a spectacular light show, similar to what lightning strikes look like. However, cockpit window static electricity discharges are harmless. The charge remains until it is able to electrically discharge on its own.

What causes airplane static electricity?

When the airplane flies through the atmosphere electricity build up on the different surfaces of the airplane. The electricity are uncharged particles created by the atmospheric presence of things such as moisture, snow, dust and ash.

How do airplane wing static wicks work?

Airplane wing static wicks act to allow the static electricity, or the excess electrons building up along the airplane wings to flow back into the atmosphere. This as opposed to allowing the static buildup to remain on the wing surface. The airplane wing static wicks also function to prevent a potentially excessive electron-buildup around the wings, since the aircraft fuel tanks are located in the aircraft’s wings.

Is airplane cockpit window static electricity dangerous?

No, airplane cockpit window static electricity is not dangerous. The “electricity” consists of harmless electrons that are naturally discharging. The discharges, in turn, can appear like a light show, appearing like the impression of lightning strikes.


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