Spirit AeroSystems Holdings, Inc. is a non-original equipment manufacturer (OEM) manufacturer of aerostructures, serving markets for commercial airplanes, military platforms and business/regional jets. The Company operates in three segments: Commercial, Defense & Space, and Aftermarket. The Commercial segment includes the design and manufacturing of forward, mid, and rear fuselage sections and systems, struts/pylons, nacelles (including thrust reversers) and related engine structural components, wings, and wing components (including flight control surfaces), as well as other miscellaneous structural parts for large commercial aircraft and/or business/regional jets. The Company's Defense & Space segment includes design and manufacturing of fuselage, strut, nacelle, and wing aerostructures (primarily) for United States government defense programs. The Company's Aftermarket segment includes design, manufacturing, and marketing of spare parts and maintenance, repair, and overhaul services.