 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
h&jeuropa
Joined: 07 Nov 2006
Posts: 645
|
 Posted: Sun Jun 03, 2018 8:08 am Post subject: Static problem? |
 |
|
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 what’s the opinion on static wicks?
Jim & Heather
| | - The Matronics Europa-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Europa-List |
|
|
|
| Back to top |
|
 |
rlborger(at)mac.com
Guest
|
| Posted: Sun Jun 03, 2018 9:11 am Post subject: Static problem? |
|
|
Jim & Heather,
I haven’t 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. It’s 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 isn’t 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. (I’m 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, aren’t 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 don’t 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(at)mac.com
On Jun 3, 2018, at 11:08 AM, h&jeuropa <butcher43(at)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 whatâs the opinion on static wicks?
Jim & Heather
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480604#480604
| | - The Matronics Europa-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Europa-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
