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. It operates through three segments: Commercial, Defense & Space, and Aftermarket. Its Commercial segment includes the design and manufacturing of forward, mid and rear fuselage sections and systems, struts/pylons, nacelles and related engine structural components, wings and wing components, as well as other miscellaneous structural parts for large commercial aircraft and/or business/regional jets. Defense & Space segment includes the design and manufacturing of fuselage, strut, nacelle, and wing aerostructures for United States Government defense programs, including Boeing P-8, C40, and KC-46 Tanker. Aftermarket segment includes the design, manufacturing, and marketing of spare parts and maintenance, repair, and operations (MRO) services, repairs for flight control surfaces and others.