Towards the end of World War One, the US Navy was looking for a long range aircraft design that could be used for convoy protection. The Curtiss Aeroplane and Motor Company received contracts to build four large flying boats for this purpose. The four aircraft were numbered NC-1 through NC-4. The NC-1 first flew on October 4, 1918 powered by three 400hp Liberty engines and in November set a world record by carrying 51 passengers. It was decided to add a fourth engine and NC-2 was equipped with two pairs of tandem engines. That was not quite the right formula and so the design was again reworked. NC-3 and NC-4 were both equipped with three tractor and one pusher engines. Since the war had ended it was decided to test the range of the new flying boats in another manner, a trans-Atlantic crossing. On May 16, 1919 three of the four, NC-1, NC-3 and NC-4, left Trepassey Bay, Newfoundland bound for the Azores, the longest leg of the flight at 1,400 miles (2,250km). Breakdowns caused NC-1 and NC-3 to land at sea and they did not continue, however, NC-4 made it to the Azores and on May 20 took off for Portugal to complete the first aerial crossing of the Atlantic Ocean. On April 31, 1919 the NC-4 was flown to Plymouth, England before returning to the USA. This historic aircraft is fully restored and is on display at the National Museum of Naval Aviation at Pensacola NAS. The museum has free admission.