PPRuNe Forums - View Single Post - Composites and lightning discussion (extracted from AF A330 thread)
Old 1st Jun 2009, 18:15
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deSitter
 
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Just to clarify the physics - in a metal, the current must flow over the surface - so everything inside is completely protected in an all-metal airplane (assuming good corrosion maintenance). In CFC, a poor conductor, the current can penetrate into the body of the material and create tremendous heat, destroying the material through explosive fragmentation and vaporization. Once a tall tree in my front yard took a large lightning strike. The 100 ft tree was reduced to a 10 ft stump and pieces of it were found a block away. No piece larger than a football was found. The remaining wood fibers were splayed out like an old paint brush. The same thing can happen to CFC, completely disrupting air flow around the damaged area. My guess is that one way or the other, composites are involved here, either through direct structural failure or otherwise, and we're looking at an industry-changing event.

-drl
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