From what I have learnt, static wicks need to have a high resistance
What next is right. For bonding and RF reference you want a ver low resistance. For static systems you want a high resistance. If you take a close look at these wire static wicks they have a resistor in the base. Others common ones are a pen like plastic tube with conductive paint (high resistance). Most aircraft tires are also slightly conductive to prevent the buildup of static electricity.
Static wicks often seem neglected. Some people tend to play with them, or walk agains them etc. Especially those with conductive paint are very fragile, when the paint is cracked they become unserviceable. Al lot of aircraft fly with these with large white spots (paint gone) which means the static weak is inoperative.
What resistance should it be?
I have not found any noise issues with my two non-resistor ones on the elevator, though the others are still original.
It varies between different manufacturers, somewhere from a couple of MegaOhms upto tens of MegaOhms would do
I have just tested the original Socata wicks on the TB20 and all of them are just wire – no resistors.
In the US (Hayward) an inspector declared an aircraft at American Flyers non-airworthy because of a missing baggage net which was on the weight-and-balance sheet.
Yes, so you add back the baggage net and you’re done. For that reason I would not hesitate to replace 1950s GE light bulbs with LEDs and similar things. Nobody will care and if somebody does, I can swap it back in a minute.
I would be very careful with that when dealing with an FAA registered plane outside of the US …
I know of a case where a FAA registered, UK based 172 was grounded by in France by French authorities because of a minor airworthiness discrepancy.
The owner/operator had to pay a couple of thousand €uros to get a DAR to come over and inspect the plane to pronounce it airworthy before flying it out.
Can you post any details, Michael?
What was the issue with it and how was it discovered?
Did he do something to p1ss off the DGAC?
A friend asked me about static wicks and whether the central core is a spark plug lead would be suitable for use as a static wick? Eliminates the corrosion of wire problem etc. Anyone have any thoughts on this?
A friend asked me about static wicks and whether the central core is a spark plug lead would be suitable for use as a static wick? Eliminates the corrosion of wire problem etc. Anyone have any thoughts on this?
@Kim – why would you want to use the rod from a spark plug, and why would corrosion be an issue?
See further back this thread which shows one simple construction method. Those wicks last for many years and I can confirm there is no evident radio interference. Also, as mentioned further back, Socata wicks are just a plain piece of wire. No resistor.
We have had several threads here on static wicks (I have just merged them) and none of them are conclusive on whether the resistor (which is present in some brands but NOT those used by Socata) does anything useful. One can come up with various theories…
Can anyone offer any theory for what the resistor might do?
I can see that it, together with the capacitance between the airframe and the rest of the universe, might help create a lowpass filter, preventing the RF from the corona discharge taking place at the end of the wick reaching the airframe.
Does anybody happen to know how this is handled on a wood wing, steel frame fuselage aircraft like the Bellanca Vikings? Obviously these are used with IFR operations as a primary function, but I haven’t a clue how they’d do it… Nor do I know much about the subject in general.
Does the Viking not have static wicks connected to the tube frame?
Can anyone offer any theory for what the resistor might do?
I can see that it, together with the capacitance between the airframe and the rest of the universe, might help create a lowpass filter, preventing the RF from the corona discharge taking place at the end of the wick reaching the airframe. But for that to work, the resistor would need to itself withstand a high voltage, which the normal metal film ones can’t do because of the spiral construction. They break down at something like a few kV. One would have to use a solid (e.g. moulded carbon) resistor.
Does anybody happen to know how this is handled on a wood wing, steel frame fuselage aircraft like the Bellanca Vikings? Obviously these are used with IFR operations as a primary function, but I haven’t a clue how they’d do it… Nor do I know much about the subject in general.
Does the Viking not have static wicks connected to the tube frame?
Peter I was referring to the carbon fibre in the plug lead, not the plug. Reason… It doesn’t corrode as even copper wire does.
How difficult is it to add static wicks to a plane that does not have them? In this case, I’m talking about a Socata Rallye MS893E. The POH permits the plane to be flown IFR with proper avionics, but I see no external sign of static wicks.
Does EASA require them for IFR flight? (I do not believe the FAA has this requirement.)
