Methods for diverting lightning current from skin fasteners in composite, non-metallic structures

METHODS FOR DIVERTING LIGHTNING CURRENT FROM SKIN FASTENERS IN COMPOSITE, NON-METALLIC STRUCTURES A multilayer composite structure (52) with integrated fastener- to-conductive layer surface lightning protection interconnection employs a conductive layer (72) with an inner surface (61) and a plurality of chamfered recesses (68) forming countersinks (74) in an outer surface (59). A carbon-fiber reinforced plastic (CFRP) composite layer is disposed on the inner surface (61) of the conductive layer (72) and conforms to the surface shape. A plurality of holes (70) extend through the plurality of chamfered recesses (68) in the conductive layer (72) and the adjoining CFRP composite layer in a manner such that the conductive layer (72) defines a countersink portion extending into the openings of the plurality of holes (70). The chamfered recesses (68) in the conductive layer (72) provides an electrically conductive surface area that contacts conductive countersunk fasteners installed within the plurality of holes (70) to enable current sharing between groups of neighboring fasteners (78).