Physics:Static wick
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.[1]
Function
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.[2]
History
Static dischargers were first proposed in a patent application by Howard Dudley Blanchard in 1920.[3] 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.[1]
See also
- Pan Am Flight 214
- TWA Flight 891
- Precipitation (meteorology)
- Electrostatic discharge
- Triboelectric effect
- Ground loop (electricity)
References
- ↑ 1.0 1.1 "This Is What Those Skinny Metal Rods Sticking Off Of A Plane Are For" (in en-us). https://jalopnik.com/this-is-what-those-skinny-metal-rods-sticking-off-of-a-1848436120.
- ↑ Pia Bergqvist (March 11, 2013). "Check Your Wicks". Flying Magazine. http://www.flyingmag.com/technique/tip-week/check-your-wicks. Retrieved March 13, 2017.
- ↑ Blanchard, Howard Dudley. "Aircraft". http://www.aeroelectric.com/Reference_Docs/Patents/Static_Dissipation/1419261_Static_Dissipation.pdf.
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