Prestwick Airport is a major international freight hub and is the only airport in Scotland to be connected by rail. It also has the second-longest runway in Scotland, accommodating all types of aircraft with no requirement for future extension. Prestwick sits in third place after Glasgow International and Edinburgh Airports in passenger traffic terms, and in 2016 was selected to become one of Europe's first spaceports. Its aviation history began in 1913 when it was developed as a pilot training airfield for the Royal Flying Corps, and during the Second World War it was involved in fitting and maintaining military aircraft delivered from the USA. Post-war, it retained a military role, building STOL (short takeoff and landing) utility aircraft, while a civilian airport grew alongside to accommodate commercial air travel. Prestwick quickly achieved the status of the transatlantic gateway to Scotland, prompting major expansion work in the 1960s to keep pace with the rising number of passengers.