The Junkers Ju 52/3m (nicknamed Tante Ju ("Aunt Ju") and Iron Annie) is a transport aircraft that was designed and manufactured by German aviation company Junkers. Development of the Ju 52 commenced during 1930, headed by German aeronautical engineer Ernst Zindel. The aircraft's design incorporated a corrugated duralumin metal skin as a strengthening measure, which was very unusual at the time. The Ju 52's maiden flight was performed on 13 October 1930. It was initially designed with a single engine, however, it was produced in quantity as a trimotor. The primary early production model, the Ju 52/3m, was principally operated as a 17-seat airliner or utility transport aircraft by various civil operators during the 1930s. Following the rise of Nazi Germany, thousands of Ju 52s were procured as a staple military transport of the nation. The Ju 52/3mg7e was the principal production model. The Ju 52 was in production between 1931 and 1952. In a civilian role, it flew with over 12 airlines, including Swissair and Deutsche Luft Hansa, as both a passenger carrier and a freight hauler. In a military role, large numbers flew with the Luftwaffe, being deployed on virtually all fronts of the Second World War as a troop and cargo transport; it was also briefly used as a medium bomber. Additionally, the type was deployed by other nation's militaries in conflicts such as the Spanish Civil War, the Chaco War, and the Portuguese Colonial War. During the postwar era, the Ju 52 had a lengthy service life with numerous military and civilian operators; large numbers were still in use by the 1980s. Even in the 21st century, several aircraft have remained operational, typically used for purposes such as heritage aviation displays and aerial sightseeing. The Ju 52 had a low cantilever wing, the midsection of which was built into the fuselage, forming its underside.[9][1] 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". 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 Ju 52 featured an unusual corrugated duralumin metal skin, which had been pioneered by Junkers during the First World War; the corrugation served to strengthen the whole structure over a smoother approach. The fuselage was of rectangular section with a domed decking, comprising a tubular steel structure that was entirely covered by the corrugated metal skin. A port-side passenger door was placed just aft of the wings; this entrance also acted as a loading hatch for freight, the lower half functioning as a platform to ease cargo movements. The cabin had a dimensional capacity of 590 cubic feet, and was lined with numerous windows stretching forward to the pilots' cockpit. The main undercarriage was fixed and divided; some aircraft had wheel fairings, others did not. A fixed tailskid, or a later tailwheel, was used. Some aircraft were fitted with floats or skis instead of the main wheels. A total of 4,845 aircraft of all variants was built. For details of the development, operational history and 28 civil and 21 military variants, click here.