The Dornier Do X passenger airship with a take-off mass of 48 tonnes was in its time the largest aircraft in the world by far. It was built in metal and operated by the "Do-Flug AG" in Altenrhein on Lake Constance in Switzerland. At the beginning it was intended for military use as a naval long-range aircraft. On 21 October 1929 the Do X took off on a round trip with a ten man crew and 159 works employees. At that time the number of people it carried was a sensational record that stood unbroken for 20 years. On 5 November 1930 it took off on an international promotional flight intended to demonstrate the luxurious comfort and safety of the Do X. The journey went from Amsterdam, via England, France, Portugal and Gran Canaria as far as Portuguese Guinea. After the Atlantic crossing the airship landed in the bay of Rio de Janeiro. The machine then flew to New York. The return flight ended with a landing on Lake Müggel in Berlin on 24 May 1932. For a whole month the mighty Do X was an attraction for all Berliners. Innumerable pleasure steamers and small boats thronged round the flying boat. Over a million people looked it over on the subsequent German roundtrip. At the end of 1934 the German Ministry of Aviation discontinued the passenger flights. From 1935 the machine was held in the "German Aviation Collection" in Berlin until it was destroyed in 1945.