Spirit AeroSystems designs and manufactures aerostructures for commercial and military aircraft. The company posted $7.2 billion in sales in 2018. Spirit divides its business across three units: fuselage systems (55% of 2018 revenue), propulsion systems (24%), and wing systems (21%). The company is the largest independent supplier of aerostructures worldwide, and its primary customer continues to be Boeing (about 80% of revenue), mainly as a result of Spirit being spun out of Boeing in 2005.
