SACHEON, South Gyeongsang Province - On the afternoon of May 9, more than a dozen engineers were busily working on the assembly lines at a manufacturing plant of the Korea Aerospace Industries (KAI). Based in Sacheon, South Gyeongsang Province, around 430 kilometers away from Seoul, KAI is the country's sole aircraft maker. The fixed-wing aircraft production facility, measuring 21,600 square meters in area, is where KAI's fighter jets are manufactured.