At the beginning of the 20th century, the combination of the internal combustion engine and a better understanding of aerodynamics led to the creation of the first airplane. The Wright Flyer, launched in 1903, flew 120 feet in a 12 second flight. By 1919, though, the Curtiss NC-4 had crossed the Atlantic, and military aircraft had flown several thousand sorties over the skies of Europe. Within a decade, the airplane and carrier redefined sea warfare, and by 1939, the airplane had become an integral portion of every armed force.