engineering

Static wick

Static wick is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Static wick rather than just read about it. In short: Static wicks, also called static dischargers or static discharge wicks, are devices used to remove static electricity from aircraft in flight. They take the form of small sticks pointing backwards from the wings, and are fitted on almost all civilian aircraft.

Key takeaways

Static wick belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Static wick to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Static wick from memory before moving on to harder problems.

Reference excerpt

Static wicks, also called static dischargers or static discharge wicks, are devices used to remove static electricity from aircraft in flight. They take the form of small sticks pointing backwards from the wings, and are fitted on almost all civilian aircraft.

Function Precipitation static is an electrical charge on an airplane caused by flying through rain, snow storms, ice, or dust particles. Charge also accumulates through friction between the aircraft hull and the air. When the aircraft charge is great enough, it discharges into the surrounding air. Without static dischargers, the charge discharges in large batches through pointed aircraft extremities, such as antennas, wing tips, vertical and horizontal stabilizers, and other protrusions. The discharge creates a broad-band radio frequency noise from DC to 1000 MHz, which can affect aircraft communication. To control this discharge, so as to allow the continuous operation of navigation and radio communication systems, static wicks are installed on the trailing edges of aircraft. These include (electrically grounded) ailerons, elevators, rudder, wing, horizontal and vertical stabilizer tips. Static wicks are high electrical resistance (6–200 megaohm) devices with a lower corona voltage and sharper points than the surrounding aircraft structure. This means that the corona discharge into the atmosphere flows through them, and occurs gradually. Static wicks are not lightning arresters and do not affect the likelihood of an aircraft being struck by lightning. They will not function if they are not properly bonded to the aircraft. There must be a conductive path from all parts of the airplane to the dischargers, otherwise they will be useless. Access panels, doors, cowls, navigation lights, antenna mounting hardware, control surfaces, etc., can create static noise if they cannot discharge through the static wick.

History

Static dischargers were first proposed in a patent application by Howard Dudley Blanchard in 1920. At this time most aircraft were constructed from cloth and wood, and rigid body airships were widely used. Therefore, a method of gradually discharging static accumulation was necessary since static discharge on these craft could cause serious damage and start fires. Static discharge is the likely cause of the Hindenburg disaster. The first static wicks were developed by a joint Army-Navy team led by Dr. Ross Gunn of the Naval Research Laboratory and fitted onto military aircraft during World War II. They were shown to be effective even in extreme weather conditions in 1946 by a United States Army Air Corps team led by Capt. Ernest Lynn Cleveland. Dayton Granger, an inventor from Florida, received a patent on static wicks in 1950.

See also Pan Am Flight 214 TWA Flight 891 Precipitation (meteorology) Electrostatic discharge Triboelectric effect Ground loop (electricity)

References

Illustrations

Worked examples

Example 1 — a first encounter with Static wick

Start with the simplest possible case. Write down what Static wick claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Static wick before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Static wick ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Static wick

In research: Static wick appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Static wick in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Static wick is common in secondary-school and first-year university syllabi. It links to neighbouring topics Electrical engineering, Electrodes, so understanding it makes those chapters shorter.
In everyday life: Look for Static wick outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Static wick in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Static wick means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Static wick out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Static wick in simple terms?

Why does Static wick matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Static wick?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Static wick.