||The Sunderland was a maritime patrol aircraft developed from Short's Empire flying boat, built as a passenger airliner in the 1930s. The prototype first flew in October 1937, and the first production model entered service with the Royal Air Force (RAF) in June 1938. In May 1939, it was decided to equip two Royal Australian Air Force (RAAF) squadrons with Sunderlands. Personnel from the first of these - 10 Squadron - were in the United Kingdom, preparing to take delivery of their aircraft when the Second World War broke out. A second Sunderland squadron - 461 - was formed in Britain in 1941.
During the war the Sunderland was employed by the air forces of Australia, Britain, and Canada. It was used principally to escort merchant convoys and hunt enemy submarines in the Atlantic Ocean, and destroyed over 60 U-boats. Belying its somewhat unwieldy appearance, the Sunderland was heavily armed and able to give good account of itself when attacked, which led to German aircrew nicknaming it "the flying porcupine". Many improvements were made to the Sunderland during its career, including the fitting of air-to-surface radar, increased armament, and more powerful engines. Several of these modifications resulted from trials carried out by the RAAF Sunderland squadrons.
Sunderlands also served in the Mediterranean, South-East Asian, and Pacific theatres, and as well as their maritime patrol role they were employed as long-range transport aircraft. It was in this latter capacity that 40 Squadron RAAF operated Sunderlands around northern Australia and New Guinea in 1944 and 1945. In all, 749 Sunderlands were manufactured up until production ended in 1946. The last Sunderland was retired from Australian service in 1947 although the type continued serving with the RAF until 1959.