Forwarded from bounce bin. Message is from
"Jouko Nikko" <jnikko@sgic.fi>
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Hi Europa Folks
I got message below from Raimo Toivio. I build Lancair IV and this
subject have pop up several times on our discussion forums.
Even conductive garbon structure cannot withstand lightning strikes.
Lightning burns about 1-5 inch (2,5-13cm) hole in garbon strukture.
On glassfiber strukture results are even lot worst. I have seen those
experiments from NASA in Sun&Fun and Oskosh conventions.
Now Columbia is certificated aircraft and it have to stand those strikes
that might happend when unvice general aviation pilots might put those
fine planes. In Columbia that mesh is laminated below celcoat, so it
doesnt add moore weight than mesh itself will bring.
It is practically impossible to put copper mesh in this stage when you
allready have finnidhed parts. Think first how many sq ft surface area
is there on your plane... Think how much epoxy you need to glue it on
plus all that extra sanding and finnishing work. Even lightest copper
mesh will weight moore than anybody is willing to put on their planes.
One moore thing: Mesh should be on outer surface to make its work
properly and even then if You got lightning (carbon+copper mesh)
strike it will make hole that might be only 1/16-1/2 inch in diameter.
What if under that point is your fuel tank?
For us the only way is to be smart enough. Avoid all buildups.....
My plan is to use stormscope to keep distance of those giants.
Jouko Nikko
jnikko@sgic.fi
The Lancair Columbia I hear includes, in the fiberglass sandwich, a
layup of metal mesh, interconnected by some means.
Even if a method is available to he homebuilder, there's no way to
test it, except in conditions that can crash the plane for other
reasons.
Regards,
Fred F.
A063, N3EU
It seems the ideal would be to "have the entire exterior surface highly
conductive and electrically continuous".
It all seems to be a difficult or almost impossible exercise (and
expensive) exercise on composite aircraft.
Is there anyone about please who doing anything about lightning risk on
their Europa?
JR (Bob) Gowing UK No 327
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