Jim & Heather,
I havent had that problem so this is all theory from a 70 year old physicist.
This is a really complex problem. You are flying a plastic, non-conductive
airframe.
Flying it through the air is like rubbing a plastic rod with a piece of
fur. Its going to generate a static charge. The charge resides on the outer
surface of the skin. No charge on the inter surface. Makes the skin of the
aircraft like a big capacitor. Because the airframe is non-conductive that
charge
isnt going to move around much until it reaches a breakdown voltage somewhere
and you can get a local discharge. Like through a an audio panel. Static
wicks out on the tips of the wings and empennage, even when connected with
conductive
media to the ground, will only dissipate the charge locally around the
wick. (Im not sure how well) And, I guess, maybe around the near field of
the conductor if it were bare wire. Would those wicks dissipate the charge that
took out the audio panel? Maybe, but probably not. Might those wicks reduce
the overall charge and prevent a charge build up to ensure that there was never
sufficient charge to harm the electronics? Maybe, maybe not.
And, arent wicks supposed to dissipate the static charge off the airframe into
the air, not to aircraft ground? The idea being NOT to get the charge buildup
in the ground. I really dont see any benefit from static wicks on a plastic
airframe.
Perhaps a better answer would be from Bob N. our electronics guru. He probably
has far more direct experience with this type of issue.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (130 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP, Hercules Prop.
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger@mac.com
On Jun 3, 2018, at 11:08 AM, h&jeuropa <butcher43@att.net> wrote:
Two or three years ago our Garmin GMA 340 audio panel was damaged apparently by
nearby lightning strike - we saw flash in far distance and then had to use
copilot
ptt. Garmin repaired for $600 and said it was destroyed by lightning.
On our trip to Petit Jean we were in some precipitation and getting bounced.
ADSB
was showing lots of colors but it was just a short distance and ATC had opposite
direction VFR traffic above us. Suddenly, no audio again. When we were
in the clear we found we could transmit by powering off the GMA 340 and hear
ATC with it powered on but in PA mode.
We talked to SteinAir and purchased a new Garmin GMA 240 audio panel partly in
hopes that the newer technology might be more resistant to being damaged and a
new 240 was about the cost of repair of the 340.
Stein, the owner, suggested we might want to add a single static wick to each
wingtip
and the top of the tail and connect them all together to our common ground
point using #20 or so wire. The idea to drain off built up charge.
Has anyone else had a similar problem and whats the opinion on static wicks?
Jim & Heather
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