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Old February 27th 08, 11:14 PM posted to rec.aviation.soaring
jcarlyle
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Posts: 522
Default Grounding of control tubes/cables

Poking around inside my fiberglass glider, I discovered a ground lead
from the rudder pedal/cable assembly to the negative electrical system
bus bar. Interestingly, there was no corresponding ground lead to the
metal aileron/elevator control rods.

Searching past posts to RAS, I discovered threads talking about the
lightning induced destruction of the London Gliding Club K21. In this
incident it appears that the metal aileron control rods were the prime
cause of the glider's disintegration. In the safety recommendation
section Schliecher was quoted as saying non-conducting aileron tubes
near the ends of the control circuits might be benefical. Another
thread mentioned the factory insertion of metallic mesh into the outer
skin layers of the Beech Starships to lessen the effect of lightning
strikes. But I couldn't find anything about bonding metal control
tubes/cables to the ground of the electrical system.

Questions:
1. What is the purpose of such bonding? Would it help at all with
lightning protection, or is it intended only to lessen static
discharge noise in the radio and other electrical systems?
2. If bonding is useful, shouldn't all of the glider's control tubes/
cables be bonded?
3. What would be the recommended method to effect a bond to aileron
and elevator rods?

-John