A power generation system for integration into an aircraft system, including a secondary power supply device having a generator turbine arranged in a duct running between a forward opening and a rearward opening on the fuselage of the aircraft. One or more support elements, defining the exo-skeleton, are attached to the tubular graft, each support element extending generally peripherally around the tubular graft, each support element including generally axial segments and generally peripheral segments. The second thread portion is screwable into a second member about the screw axis and is provided coaxially with the first thread portion.