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Purpose of static discharge wicks

Aviation Mechanic Airframe (AMA) practice question 11 of 26 on Communications, Light Signals, and Runway Lighting Systems. ACS element AM.II.I.R4 · difficulty: recall. Want to answer it in a timed quiz? Use the Aviation Mechanic Airframe (AMA) practice mode.

Question bank updated 2026-09-22

QUESTIONStatic dischargers, or wicks, are installed on an aircraft to reduce what problem?

  1. ARadio receiver interference
  2. BLightning strike damage
  3. CCorrosion of the trailing edges
Show the answer and explanation

Correct answer: A. Radio receiver interference

  • A — correct The handbook states static dischargers are installed to reduce radio receiver interference caused by corona discharge from precipitation static.
  • B — incorrect Dischargers bleed off precipitation static; they are not a lightning protection device.
  • C — incorrect Corrosion control is unrelated to the electrical function of a static discharger.

BACKGROUND

An aircraft surface becomes highly charged with static electricity in flight, and the resulting corona discharge occurs in short pulses that produce noise across the radio frequency spectrum. Static dischargers, or wicks, are installed to reduce that radio receiver interference by discharging precipitation static at points a critical distance away from avionics antennas, where there is little or no coupling of the static to cause noise. They are normally mounted on the trailing edges of control surfaces, the wing tips, and the vertical stabilizer. Flexible and semi-flexible dischargers are attached with metal screws, rivets, or epoxy, and a resistance measurement from the mount to the airframe should not exceed 0.1 ohm.

STUDY TIP

Remember that static wicks protect radio reception, not the structure, and that the 0.1 ohm mount-to-airframe resistance check is separate from the 0.003 ohm bonding jumper limit.

KEY POINTS

  • Static dischargers reduce radio receiver interference from precipitation static.
  • They are mounted on trailing edges, wing tips, and the vertical stabilizer.
  • Resistance from the discharger mount to the airframe should not exceed 0.1 ohm.

SOURCES

  • FAA-H-8083-31B ch11 "Static Discharge Wicks"
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SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-31B Aviation Maintenance Technician Handbook – Airframe, and 14 CFR part 43. Regulations and handbooks are revised; confirm details against the current edition.