Spirit AeroSystems Holdings, Inc. is an independent non- original equipment manufacturer (OEM) aircraft parts designer and manufacturer of commercial aero structures. The Company operates in three segments: Fuselage Systems, which includes forward, mid and rear fuselage sections; Propulsion Systems, which includes nacelles, struts/pylons and engine structural components, and Wing Systems, which includes wing systems and components, flight control surfaces and other miscellaneous structural parts. The Company is an independent supplier of aero structures to The Boeing Company (Boeing) and Airbus S.A.S. (Airbus). The Company principally designs, engineers and manufactures commercial aircraft structures, such as fuselages, nacelles (including thrust reversers), struts/pylons, wings and wing assemblies and flight control surfaces for commercial aircrafts. The Company also designs, engineers and manufactures structural components for military aircraft.