The Vought OS2U Kingfisher is an American catapult-launched observation floatplane. It was a compact mid-wing monoplane, with a large central float and small stabilizing floats. Performance was modest because of its low-powered engine. The OS2U could also operate on fixed, wheeled, taildragger landing gear. The OS2U was the main shipboard observation seaplane used by the United States Navy during World War II, and 1,519 of the aircraft were built. It served on battleships and cruisers of the US Navy, with the United States Marine Corps in Marine Scouting Squadron Three (VMS-3), with the United States Coast Guard at coastal air stations, at sea with the Fleet Air Arm of the Royal Navy, and with the Soviet Navy. The Royal Australian Air Force also operated a few Kingfishers from shore bases. The Naval Aircraft Factory OS2N was the designation of the OS2U-3 aircraft built by the Naval Aircraft Factory in Philadelphia, Pennsylvania. The OS2U first flew on 1 March 1938. In the late 1930s, Vought engineer Rex B. Beisel was tasked with designing an observation monoplane aircraft for the U.S. Navy suitable for many tasks, including directing battleship fire. In replacing the standard biplane observation aircraft with a more modern monoplane design, Beisel incorporated innovations making it the first production type to be assembled with spot welding, a process Vought and the Naval Aircraft Factory jointly developed to create a smooth fuselage that resisted buckling and generated less drag. Beisel also introduced high-lift devices, spoilers and in a unique arrangement, deflector plate flaps and drooping ailerons located on the trailing edge of the wing were deployed to increase the camber of the wing and thus create additional lift. For combat missions, the pilot had a .30-caliber Browning M1919 machine gun, the receiver mounted low in the right front cockpit, firing between the engine cylinder heads, while the radio operator/gunner manned another .30-caliber machine gun (or a pair) on a flexible Scarff ring mount. The aircraft could also carry two 100 lb bombs or two 325 lb depth charges. Additionally, the "Kingfisher", as it was designated, served as a trainer in both its seaplane and landplane configurations. Beisel's first prototype flew in 1938, powered by an air-cooled, 450 hp Pratt & Whitney R-985-4 Wasp Junior radial engine. In April 1942 The Royal Australian Air Force (RAAF) obtained 18 Kingfishers from an unexpected source. These aircraft had been destined for the Royal Netherlands Air Force, for operation in the Netherlands East Indies, but following the capture of that area by the Japanese in March 1942 the crated aircraft were diverted to Australia. The Kingfishers were allocated to 107 Squadron and operated from RAAF Base Rathmines on the Australian east coast conducting anti-submarine patrols and seaplane flight training duties. At wars end the remaining nine aircraft were flown to the RAAF Base at Lake Boga, Victoria for storage. For more details on the operational history and variants of the Kingfisher, click here, and for details of its service in the RAAF/RAN, click here.
