Short Sunderland

The Short S.25 Sunderland was a British flying boat patrol bomber developed for the Royal Air Force (RAF) by Short Brothers. It took its service name from the town (latterly, city) and port of Sunderland in northeast England.

Based in part upon the S.23 Empire flying boat, the flagship of Imperial Airways, the S.25 was extensively re-engineered for military service. It was one of the most powerful and widely used flying boats throughout the Second World War, and was involved in countering the threat posed by German U-boats in the Battle of the Atlantic. RAF Sunderlands also saw service throughout the Korean War and continued in service until 1959. It also took part in the Berlin airlift. Sunderlands remained in service with the Royal New Zealand Air Force (RNZAF) until 1967.

Sunderlands converted for civil use, known as Short Sandringhams, continued in airline operation until 1974. A single airworthy example remains on display in Florida at Fantasy of Flight.

Development

The early 1930s saw intense competition in developing long-range intercontinental passenger service between the United Kingdom, the United States, France and Germany, but the United Kingdom had no equivalent to the new American Sikorsky S-42 flying boats or the German Dornier Do X. However, in 1934, the British Postmaster General declared that all first-class Royal Mail sent overseas was to travel by air, establishing a subsidy for the development of intercontinental air transport in a fashion similar to the U.S. domestic program a decade earlier. In response, Imperial Airways announced a competition to design and produce 28 flying boats, each weighing 18 long tons (18 t) and having a range of 700 mi (1,100 km) with a capacity for 24 passengers.