A composite structure forming a load bearing composite shell for a helicopter, with a shell which defines the exterior of a fuselage and includes a central fuselage section and a tail boom, a fuselage which is adapted house an engine or a drive train, a layered composite crashworthy seat and a support structure and a fastening structure and a method of fastening by providing an adhesive between two layers which is allowed to flow through opposing holes in the layers to provide a chemical and mechanical attachment between the layers.