Anonymous
Anonymous asked in Science & MathematicsEngineering · 4 years ago

Are static wicks really that effective in reducing static noise?

Some pilots keep on adjusting the radio or ics squelch to maximum i think that is because of static or some other noise during flight. When troubleshooting radio problems like "radio static" and "garbled transmission" i often find the squelch too high and when i minimize it, the radio would work fine during engine runup. most of the time it's good with that. but on some aircrafts, pilots would keep squawking radio problem esp noise after a few hours of flights. the weather is not that consistent nowadays so i'm thinking that could be the cause. radio works well on ground runup but after how many flights, some pilot would squawk noisy reception. static wicks are not that cheap though and i was told that's the reason why our employer don't invest on them.

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  • 4 years ago
    Favorite Answer

    (1) Yes, they ARE effective at reducing radio interference despite what the other (uninformed) people have said.

    (2) Static wicks are generally only used on faster aircraft and those designed to fly in IFR conditions. They are generally not found on light, general aviation aircraft flown in VFR conditions such as trainers used at flight schools. The addition of static wicks to an aircraft that does not have them is not effective unless there is sufficient electrical bonding between flight control surfaces, wings, empennage and fuselage.

    (3) If not sufficiently bled off, the static charge will build over time and static interference will increase. The increase in noise is almost always associated with flight in visible moisture and it is highest when that moisture is frozen.

    (4) On aircraft with static wicks installed as standard equipment, the aircraft is considered un-airworthy if any are broken or missing. On aircraft operated using a minimum equipment list (MEL), no more than one static wick per flight control surface can be missing. On some aircraft the limitation is one per aircraft.

    (5) I personally have experienced very high communication static and the complete loss of an EFIS system due to static buildup. It occurred on our entire fleet of 10 new turboprop aircraft that had been equipped with electronic flight displays and it would occur EVERY TIME the planes were flown in snow / sleet or freezing temps in cloud (ice crystals). You could hear the static slowly build in the headset and it became so loud that communication was impossible. Then all of a sudden all the EFIS screens would shut off and re-boot. It didn't take long for me to recognize when this was going to happen but the first time it occurred it caught us by surprise. Fortunately it happened the first time in a not too critical time but it could have been quite serious had it occurred during an instrument approach in bad weather. It took the manufacturer of the aircraft months to get to the bottom of the problem and of course it could never be duplicated on the ground. The problem was that all the static wicks were mounted to control surfaces only, and there was insufficient electrical contact between the airframe and control surfaces due to improper bonding. Fortunately the aircraft had sufficient analog gauges (copilot side) that the loss of the EFIS wasn't catastrophic, but it still raised hell with communications and would cause false VOR indications. Once the bonding issue was resolved, the problem went away. The problem was caused by the aluminum structure being primed with chromate before the bonding straps were installed at the factory. Idiots!!!

    • Piero
      Lv 7
      4 years agoReport

      Your problem was with poor contact on bonding straps. Static wicks didn't add to or prevent this problem. It's been a problem with de Havilland aircraft for generations.

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  • 4 years ago

    Static wicks do prevent noise in radios, by using high resistance elements with a lower corona voltage than the surrounding aircraft structure. They control the corona discharge into the atmosphere, isolating noise and preventing it from interfering with aircraft communication equipment.

    http://www.flyingmag.com/technique/tip-week/check-...

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  • 4 years ago

    Radio static can come from several different sources in aircraft and mostly from lack of proper bonding and properly install static wicks.

    Bonding is the electrical connecting of two or more conducting objects not otherwise adequately connected. The following bonding requirements must be considered:

    • Equipment bonding—low-impedance paths to aircraft structure are normally required for electronic equipment to provide radio frequency return circuits and for most electrical equipment to facilitate reduction in EMI. The cases of components that produce electromagnetic energy should be grounded to structure. To ensure proper operation of electronic equipment, it is particularly important to conform the system’s installation specification when interconnections, bonding, and grounding are being accomplished.

    • Metallic surface bonding—all conducting objects on the exterior of the airframe must be electrically connected to the airframe through mechanical joints, conductive hinges, or bond straps capable of conducting static charges and lightning strikes. Exceptions may be necessary for some objects, such as antenna elements, whose function requires them to be electrically isolated from the airframe. Such items should be provided with an alternative means to conduct static charges and/or lightning currents, as appropriate.

    • Static bonds—all isolated conducting parts inside and outside the aircraft, having an area greater than 3 square inches and a linear dimension over 3 inches, that are subjected to appreciable electrostatic charging due to precipitation, fluid, or air in motion, should have a mechanically secure electrical connection to the aircraft structure of sufficient conductivity to dissipate possible static charges. A resistance of less than 1 ohm when clean and dry generally ensures such dissipation on larger objects. Higher resistances are permissible in connecting smaller objects to airframe structure.

    Static dischargers

    Devices connected to the trailing edges of control surfaces to discharge static electricity harmlessly into the air. They discharge the static charges before they can build up high enough to cause radio receiver interference.

    Reference FAA Handbook FAA-8083-31 Chapter 9

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  • JetDoc
    Lv 7
    4 years ago

    Static wicks are there to disperse static electricity from the hull and control surfaces of the aircraft. They have nothing to do with static noise on the radios.

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  • Dick
    Lv 7
    4 years ago

    "Static" wicks have nothing to do with radio noise. Two different problems.

    Source(s): A&P since 1954 and 1st class FCC, with 40 years hands on experience
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  • Nomadd
    Lv 7
    4 years ago

    Static wicks don't reduce noise. They can make it worse, since it's the discharge of static, which happens more consistently with wicks, that causes noise. Junky radios, like Icoms, are noisier.

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  • Marc
    Lv 4
    4 years ago

    i fly a number of sep all with static wicks and have no radio problems, so i would say yes extreamly important in noise reduction

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