The NC-4 is a Curtiss NC flying boat that was the first aircraft to fly across the Atlantic Ocean, albeit not non-stop. The NC designation was derived from the collaborative efforts of the Navy (N) and Curtiss (C). The NC series flying boats were designed to meet wartime needs, and after the end of World War I they were sent overseas to validate the design concept.

John Alcock and Arthur Brown were British aviators who, in 1919, made the first non-stop transatlantic flight. They flew a modified First World War Vickers Vimy bomber from St. John's, Newfoundland, to Clifden, County Galway, Ireland. The Secretary of State for Air, Winston Churchill, presented them with the Daily Mail prize for the first crossing of the Atlantic Ocean by aeroplane in "less than 72 consecutive hours". A small amount of mail was carried on the flight, making it the first transatlantic airmail flight. The two aviators were awarded the honour of Knight Commander of the Most Excellent Order of the British Empire (KBE) by King George V at Windsor Castle a week later.