As a 20-year-old with no job prospects, DiFrancesco decided he would get licensed to work on airplanes. After having attained his certification, DiFrancesco was hired by Boeing as an airplane mechanic. When the Korean War began in 1950, he was kept particularly busy building military planes that would be used in the war. During this time he also built one of the first military helicopters, the Piasecki H-21 Shawnee/Workhorse, which were commonly called “flying bananas.”