Hugo Junkers

In 1910 Junkers patented an all-wing aircraft with unbraced, thick-profile cantilever wings, after working from 1909 with his Aachen colleague Hans Reissner on a metal-winged aircraft. His company's J 1 first flew in December 1915; the Neue Deutsche Biographie lists it as his first all-metal aircraft, with a speed of 170 km/h at just over 1,000 kg, and a regional history portal calls it the first all-metal aircraft in the world. Wartime shortages of duralumin meant it was built of sheet iron, and it was nicknamed the Blechesel, the 'sheet-metal donkey'.

In 1919 his Dessau company built the F 13, a four-seat all-metal airliner with an enclosed cabin. The Neue Deutsche Biographie says it showed all the essential features of the modern airliner and that about 300 were built; it helped start German commercial aviation. In 1921 Junkers set up an air-traffic department that became Junkers Luftverkehr, which merged in 1926 with a competitor to form Deutsche Luft Hansa.

The Ju 52, first flown in 1930 as a single-engine aircraft and from 1932 as the three-engine Ju 52/3m, became known worldwide as 'Tante Ju' (Aunt Ju). The Neue Deutsche Biographie describes it as a 17-passenger airliner, the last aircraft to arise from Junkers's personal initiative, the standard airliner of Deutsche Lufthansa before 1939, and until the early 1940s the most-built airliner in the world; a newspaper feature counts almost 5,000 built after 1932.

Before aircraft, Junkers worked on gas engines at Dessau and in 1892 patented, with Wilhelm von Oechelhaeuser, a horizontal two-stroke opposed-piston gas engine. In the same year he patented the calorimeter, which measures the heating value of gas, and from it developed the gas bath heater and the water heater; his firm Junkers & Co. was founded in Dessau in 1895. He built an opposed-piston oil engine in 1908, founded Junkers Motorenbau in 1923, and in 1929 produced the first diesel aircraft engine. The heater business paid for his later research.

On 11 January 1916 Junkers asked the army aviation inspectorate for money to develop the J 1 further; the war ministry ordered six more aircraft at 25,000 marks each. Between August and October he sent it a series of long letters, and he asked again for an advance on 6 October and 19 December. The ministry replied that orders would follow once his aircraft were ready for the front. Byers records that by early 1917 he had put over 1.5 million marks of his own money into aircraft research. An order for fifty J 4 aircraft came on 20 March 1917.

Repeating the requests over a year, and continuing development with his own money while they went unanswered, is consistent with persistence; the account rests on one scholarly study drawing on his own letters. Persistence

After army officials forced a joint company on him and Anthony Fokker in October 1917, Junkers refused Fokker's demand to run its operations and insisted that the patented wing could be used only by the new company. In April 1918 he drafted a letter to the inspector of flying troops complaining that the board was setting research priorities and allocating money for his research institute, and noted that he intended to take the institute back into his own firm. The joint company was formally dissolved on 24 April 1919.

Resisting outside control over his research and its funding is consistent with a strong need for autonomy; Byers also reports that army officials saw the same stance as a lack of deference. Need for Autonomy

The 1932 world economic crisis pulled Junkers's group of companies into financial trouble. To save the aircraft and engine works he sold his original water-heater firm, Junkers & Co., to Robert Bosch. In October 1933 the National Socialist government forced him to transfer the majority of the shares in his aircraft and engine companies to the Reich and to leave their management. He spent his remaining years on private research into metal building, and died in 1935.

Selling the firm that had financed his research in order to keep the aircraft and engine works going is consistent with resourcefulness; the 1933 transfer is recorded as an event and is not a basis for any trait. Resourcefulness