What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Static Wicks?

ppilotmike

Well Known Member
Are you guys installing static wicks on your airplane? If so, where? I saw a post of a guy with a 10 installing wicks on his rudder. I know they are important for reduction of electrical interference, but I don't recall seeing many wicks on RVs. I'll be starting my wings soons, and started thinking about the fact that I currently don't have wicks on my elevators or rudder. Is this a problem?
 
You don't need them

You don't need them. You're not going to build up much of a static charge going 200mph. Do you want the extra drag? Install them then.
A guy I work with at Gulfstream has vortex generators on his car. Maybe I should suggest static wicks to him.
 
How did you come to that decision?

I did not see any on the factory planes and there are very few -10 builders using them as far as I can determine. In fact, they were not even mentioned in the plans as an option to install. If it's good enough for Van's planes, it's good enough for mine. If there is an issue when I get mine in the air, I will deal with it then. But that's just me. I'm building light and simple. Your mission may differ.
 
Static wicks

Cessna discovered that static wicks could be lifesavers in keeping some
Kinds of electrical storms from blanking out communications. This is from
An engineer! A friend, who worked for cessna more than 20 years ago.
Bill
 
Don't jump to the conclusion that they are not needed for a slow plane. I had to install them on my Piper Archer (yes 128 kts) I had all of my radios go silent flying IMC on two occasions. I also noticed my BFG Stormscope used to have random targets displayed prior to the wicks being installed. Fortunately the Archer has a static wick option which I installed. My issue no longer exists with the wicks installed 2100 hours later.
My guess is using your rationale, a non-jet does not need to be grounded during fueling.

I started a thread in the Comm or EFIS area regarding installing them here http://www.vansairforce.com/community/showthread.php?t=83448
I regret not having put the hooks in place during the build process to install them. I certainly will install them.
 
wicks

Go ahead and install them if you want. Have fun. Hope you have everything bonded or they are pointless.
 
rationale

And where did you come up with the grounding during fuel thing. Boy you must be smart.
 
None on mine

It is not that I don't think they serve a good purpose. I wanted to keep the cost, weight and build time down. I had to rent old 172's and build a family hauler on a limited budget. If one has the time, money and desire, go for it. I don't have an ifr ticket and I fly in a very humid area of the country. If I get the ifr ticket and have an occurence like Bill, then I will probably install them. I don't think speed has as much to do with it as does the atmosphere...heck I shock myself all the time walking across carpet in the winter and I am only moving 2 or 3 kts. Keep building guys and lets do some trips together.
 
I chose to install them on mine, largely because there was significant anecdotal evidence in the forums that people in similar-performance aircraft had had issues with interference which were alleviated when wicks were added.

The particular parts I choose will allow the wicks to be removable, leaving very little visible or aerodynamic change to the airframe, so I will be able to test performance with and without the wicks. The total weight of additional components I'm adding to the build I would estimate at around 0.5 pounds, so the weight argument is essentially moot. There is a bit of additional labor getting the added nutplates and stiffeners fabricated and installed, but it really hasn't been significant at all thus far. The wingtips will probably be the most difficult part, and I'm coming up on that bit soon; everything else has been trivial from an effort standpoint. I definitely spent more time looking through the arguments for and against wicks and planning my install than I did actually performing the modifications as I built. As for cost, other than the wicks themselves I'm probably looking at about $10 in additional hardware. The wicks I'm using are pricey at ~$42 each, for a total cost of $504. There are cheaper alternatives out there; I went with these because they supported the easy-removal option that I wanted.

Here's what I've done thus far: http://www.mouser.org/projects/rv-10/staticwicks.html

There is a link near the top of that page to Dayton-Granger's recommended installation positions for wicks in the RV-10.

My advice to you is to weigh the risk for yourself, and ignore the blowhards. If you choose to install them, it can be done easily, cheaply, and quickly. If you don't, and you don't fly a lot of IFR, the evidence seems to suggest that your risk of a problem is quite low.
 
Is there something more to these wicks than some wire and attachment hardware. $500 seems like a lot.


As a data point.
I did not build our 10 but it does not have wicks and I am not aware of any problem after about 150 hours.
 
Well, $500 is for 12 of them as recommended for this airframe by the manufacturer. $42 a piece is still pretty steep, but then again these are TSO'd hardware.

The physics behind a static discharge device basically require that the conductive point(s) at the tip be as sharp as possible in order to maximize the rate of release of charge from the conductor to the surrounding atmosphere. While this can be done with non-zero efficiency with a standard wire, modern static wicks for small aircraft employ a bundle of ultra-fine metal fibers or conductive glass fibers at the tip in order to maximize efficiency.

The wicks will discharge your charged airfrarme at some rate that is proportional to the charge on the skin and to the wick efficacy. If the rate of discharge from the wicks is less than the rate of charge accumulation, then you'll build up a static charge on the airframe and possibly have issues with your electronics. The only ways to increase the rate of discharge are to add more wicks, move the wicks to areas of higher charge concentration, or use more effective wicks.

I choose to buy reasonably high-tech wicks with ultra-fine conductive fibers on the tips in order to maximize my odds of having sufficient discharge capacity. In the grand scheme of things, $500 is only a quarter of a percent of the cost of the aircraft. If adding wicks gives me some extra safety margin against my all-electronic control panel going wonky on me, that seems like it is worth an extra 0.25% to me. Your mileage will almost certainly vary.
 
Back
Top