Protection Against the Direct Effects of Lightning Strikes for a Carbon Fiber Composite Aircraft

Presently, many manufacturers are replacing aluminium with fiberglass, Kevlar, and carbon fiber composites (CFC) to take advantage of the fuel savings allowed by weight reduction. It is well known that lightning strikes may cause severe damage to unprotected composites, so protective measures must usually be incorporated. Presently available methods involve application of a layer or ply of conductive material to the laminate, which compromises the original weight savings and sometimes imposes manufacturing and repair difficulties. These drawbacks have been especially severe for thin laminates, where the weight of the protective layer is a significant portion of the entire laminate. Thus, an effort was begun to develop more efficient lightning protective methods for CFC laminates. The outcome was a new CFC material that incorporates conductive filaments to disperse stroke and energies and to limit damage but retains the same physical and structural properties as unprotected CFC. The weight increase to this modification is extremely small, and no additional procedures are necessary in the aircraft manufacture.