Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml
Date: Sat, 01 Jun 2002 23:54:32 -0400
Message-ID: <redirect-1254020@logan.com>
From: Klusmanp@aol.com
Subject: Re: [LML] Lightning strike
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As I understand it, there are several "zones" on an aircraft that are more 
likely to get hit than others (while in flight, anyway). These are the 
extremities of the aircraft: nose, tail, wingtips, etc. The best way to 
protect an aircraft from damage due to lightning strike is to provide a path 
on the outer surface of the aircraft for the energy to dissapate. On metal 
airplanes this is as simple as making sure all control surfaces are grounded 
(ground?) to the wing/tail, wing/tail are grounded to the fuselage, engine is 
grounded to engine mount, engine mount is grounded to fuselage, etc. 

For composite airplanes you want some kind of fine wire (aluminum) screen 
mesh in one of the layers closest to the outer surface. I think carbon is 
conductive to a certain degree but the wire will greatly improve things 
further even for carbon. Carbon fiber prepreg IS available with the wire mesh 
woven in. I'm sure it is more expensive - the other downside to the 
manufacturer is that it can be harder to get the stuff to lay down in a mold 
properly.

If you don't have some means for dissipating the energy the lightning will 
tend to dwell in one spot and do alot of damage. It will possibly try to 
attach to underlying metalic pathways: wiring, fuel lines, control cables and 
pushrods, etc.

Paul Klusman


In a message dated 6/1/02 11:30:21 AM EST, glcasey@adelphia.net writes:

<<  When asked where lightning strikes someone said "wherever it
 wants." >>