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The Junkers Ju 52 (nicknamed ''Tante Ju'' ("Aunt Ju") and ''Iron Annie'') is a German trimotor transport aircraft manufactured from 1931 to 1952. It saw both civilian and military service during the 1930s and 1940s. In a civilian role, it flew with over twelve air carriers including Swissair and Deutsche Luft Hansa as an airliner and freight hauler. In a military role, it flew with the ''Luftwaffe'' as a troop and cargo transport and briefly as a medium bomber. The Ju 52 continued in postwar service with military and civilian air fleets well into the 1980s. ==Design and development== The Ju 52 was similar to the company's previous Junkers W 33, although larger. In 1930, Ernst Zindel and his team designed the Ju 52 at the Junkers works at Dessau. The aircraft's unusual corrugated duralumin metal skin, pioneered by Junkers during World War I, strengthened the whole structure. The Ju 52 had a low cantilever wing, the midsection of which was built into the fuselage, forming its underside.〔Grey and Bridgman 1972〕 It was formed around four pairs of circular cross-section duralumin spars with a corrugated surface that provided torsional stiffening. A narrow control surface, with its outer section functioning as the aileron, and the inner section functioning as a flap, ran along the whole trailing edge of each wing panel, well separated from it. The inner flap section lowered the stalling speed and the arrangement became known as the ''Doppelflügel'', or "double wing".〔Jackson 1960, p. 100.〕 The outer sections of this operated differentially as ailerons, projecting slightly beyond the wingtips with control horns. The strutted horizontal stabilizer carried horn-balanced elevators which again projected and showed a significant gap between them and the stabilizer, which was adjustable in-flight. All stabilizer surfaces were corrugated. The fuselage was of rectangular section with a domed decking, all covered with corrugated light alloy. There was a port side passenger door just aft of the wings, with windows stretching forward to the pilots' cockpit. The main undercarriage was fixed and divided; some aircraft had wheel fairings, others not. There was a fixed tailskid, or a later tailwheel. Some aircraft were fitted with floats or skis instead of the main wheels. In its original configuration, designated the Ju 52/1m, the Ju 52 was a single-engined aircraft, powered by either a BMW or Junkers liquid-cooled engine. However, the single-engine model was underpowered, and after seven prototypes had been completed, all subsequent Ju 52s were built with three radial engines as the Ju 52/3m (''drei motoren'' — "three engines"). Originally powered by three Pratt & Whitney R-1690 Hornet radial engines, later production models mainly received 574 kW (770 hp) BMW 132 engines, a licence-built refinement of the Pratt & Whitney design. Export models were also built with 447 kW (600 hp) Pratt & Whitney R-1340 Wasp and 578 kW (775 hp) Bristol Pegasus VI engines. The two wing-mounted radial engines of the Ju 52/3m had half-chord cowlings and in planform view (from above/below) appeared to be splayed outwards, being mounted at an almost perpendicular angle to the tapered wing's sweptback leading edge. The central engine had a cowling like a Townend ring as the fuselage behind it was increasing in diameter, though some later aircraft had deeper cowlings. Production Ju 52/3m aircraft flown by Luft Hansa before World War II, as well as Luftwaffe-flown Ju 52s flown during the war, usually used an air-start system to turn over their trio of radial engines, using a common compressed air supply that also operated the main wheels' brakes. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Junkers Ju 52」の詳細全文を読む スポンサード リンク
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