The Dornier Do 24 is a 1930s German three-engine flying boat designed by the Dornier Flugzeugwerke for maritime patrol and search and rescue. A total of 279 were built among several factories from 1937 to 1945. The Dornier Do 24 was designed to meet a Royal Netherlands Navy requirement for a replacement of the Dornier Wals being used in the Dutch East Indies, with the Netherlands government signing a contract for six Dornier Do 24s on 3 August 1936. Two more prototypes were built for the German navy to be evaluated against the Blohm & Voss BV 138. The Do 24 was an all-metal parasol monoplane with a broad-beamed hull and stabilising sponsons. Twin tails were mounted on the upswept rear of the hull, while three wing-mounted tractor configuration engines powered the aircraft. Fuel was carried in tanks in the sponsons and the wing centre section. Up to 1,200 kg (2,600 lb) of bombs could be carried under the aircraft's wings, while defensive armament consisted of three gun turrets, one each in nose, dorsal and tail positions. In early aircraft the turrets were each fitted with a machine gun but later aircraft carried a 20 mm cannon in the dorsal turret. Do 24 V3, the first of the Dutch X boats, as they would be called in Dutch service, took off from Lake Constance on 3 July 1937, with the second Dutch boat, Do 24 V4 following soon after. As the Dutch required that their flying boats use the same engines as the Martin 139 bombers in use in the Dutch East Indies, they were fitted with 661 kW (887 hp) Wright R-1820-F52 Cyclone radial engines. Test results were good, with the new flying boat proving capable of operating from extremely rough open seas and the Dutch placed an order for a further 12 Do 24s on 22 July 1937. Do 24 V1, the first of the two aircraft for Germany, powered by three 450 kW (600 hp) Junkers Jumo 205C diesel engines, flew on 10 January 1938 but after evaluation, the two German boats were returned to Dornier for storage. The Netherlands was enthusiastic and planned to purchase as many as 90. Of these, 30 were to be built by Dornier (with all but the first two prototypes assembled by Dornier's Swiss subsidiary based at Altenrhein). The remaining aircraft were to be built under licence in the Netherlands by Aviolanda at Papendrecht. Of these aircraft, all but one of the German and Swiss built aircraft and the first seven Aviolanda-built aircraft were to be Do 24K-1s, powered by the original R-1820-F52 engines, while the remaining aircraft were to be Do 24K-2s, with more powerful 820 kW (1,100 hp) R-1820-G102 engines and additional fuel. With the German occupation, production was paused, however while the Luftwaffe Küstenfliegergruppen Maritime reconnaissance branch was uninterested in the partially completed aircraft as they had already chosen the Blohm und Voss Bv 138 for the role, the Dutch production line resumed, to provide aircraft for the otherwise poorly equipped Seenotdienst (Sea Emergency Service), which was still operating Heinkel He 59 biplanes. The 13 airframes on the Aviolanda assembly line were completed with Dutch-bought Wright Cyclone engines but later models used the BMW Bramo 323R-2. An additional 159 Do 24s were built in the Netherlands during the occupation, most under the designation Do 24T-1. Another production line for the Do 24 was established in the CAMS factory at Sartrouville, France, during the German occupation. This line was operated by SNCAN and produced 48 Do 24s during the war and another 40 after the liberation of France, which served with the French Navy until 1952. The RAAF operated 6 Do-24, A49-1 to A49-6. For operational history and variants, click here. Note: The colour photos are the 24 ATT variant with turboprop powerplants. Surviving aircraft Australia Unknown – Do 24 K-1 forward fuselage on static display at the Lake Boga Flying Boat Museum in Lake Boga, Victoria. It was previously used as a private boat in Echuca, Victoria.