Lightning Protection of Revolving Aircraft Turrets

"Electrostatic charge dissipation poses a danger to aircraft and crew, especially in aircraft with composite structures and between two relatively moving components lacking a common ground, because destructive electrical arcs can occur. This configurationexists in the United States Air Force airborne laser (ABL) aircraft between the alloy fuselage and the composite turret. The problem is exacerbated by the presence of combustible vapors in the ABL turret area. Existing systems cannot handle the highcurrents without some arcing. Noesis, Inc. and HiPerCon, LLC have developed a safe and efficient means for transferring large quantities of electrical energy across a sliding interface using brushes constructed of hair-fine metal fibers. The innovativeapproach proposed would adapt this technology to operation under the extreme environmental conditions experienced by the ABL. Specifically, lubrication strategies and materials options would be conducted to down-select to a few primary candidates. Inparallel with this effort, environmental data would be collected to plan for systematic lab and flight testing under conditions approximating those in actual service. This technology could provide the Air Force with the lightweight, affordable, andspark-free grounding system, not only for the ABL, but also other aircraft as a back fit or forward fit installation. Development of the proposed system solution and completion of successively m