final assembly

Final assembly in the aerospace industry is the culmination of manufacturing processes where individual subassemblies are brought together to form a complete aircraft or spacecraft. This stage requires massive facilities, such as Boeing's plant in Everett, Washington, the world's largest building by volume, to accommodate the immense size of the products.12

The process typically begins with mating fuselage sections, followed by the addition of wings, engines, and landing gear. Modern assembly lines often utilize overhead rails and heavy-lift cranes, or even air-cushion techniques, to move large components. For spacecraft, final assembly occurs under strict clean-room conditions to prevent contamination, with rigorous testing to ensure all systems function correctly before shipment, as in-orbit modifications are often impossible.23