Hugo Junkers: The Pioneer of All-Metal Aircraft

Biography

Junkers was born in Rheydt in the Prussian Rhine Province, the son of a wealthy industrialist. After taking his Abitur exams in 1878, he attended the Royal Polytechnic University in Charlottenburg and the Royal Technical University in Aachen, where he completed his engineering studies in 1883.

At first, he returned to Rheydt to work in his father's company, but soon attended further lectures on electromagnetism and thermodynamics held by Adolf Slaby in Charlottenburg. Slaby placed him with the Continental-Gasgesellschaft in Dessau, where he worked on the development of the first opposed-piston engine. To measure heating value, Junkers patented a calorimeter and founded a manufacturing company in 1892. Junkers personally introduced the calorimeter at the 1893 World's Columbian Exposition in Chicago, where it was awarded a gold medal. The next year, he patented a gas-fired bath boiler, which he refined as a tankless heater. In 1895, he founded Junkers & Co. to utilize his inventions.

From 1897, he was offered a professorship of mechanical engineering at Aachen, where he lectured until 1912. Working as an engineer at the same time, Junkers taking substantial gains of Junkers & Co. devised, patented, and exploited calorimeters, domestic appliances (gas stoves), pressure regulators, gas oil engines, fan heaters, and other inventions.

Aeronautical work

Junkers' aeronautical work began in earnest at age 50 when he worked with engineer Hans Reissner in Aachen. Reissner had developed an all-metal aircraft, on which work first started in 1909 at the Brand Heath, equipped with corrugated iron wings built by Junkers & Co. in Dessau. The iron wings were patented one year later. Junkers had a wind tunnel built and invented a hydraulic brake.

He had far-sighted ideas of metal aeroplanes and flying wings, but the necessities of the war held him back. During World War I, the government forced him to focus on aircraft production. In 1915, he developed the world's first practical all-metal aircraft design, the Junkers J 1 "Blechesel" (Sheetmetal Donkey), which survived on display at the Deutsches Museum in Munich until WWII. His firm's first military production design in 1916–17 was the armored-fuselage, two-seat, all-metal sesquiplane known by its IdFlieg designation, the Junkers J.I, considered the best German ground attack aircraft of the war. During this time, the German government's IdFlieg military aviation inspectorate forced him to merge his firm with Anthony Fokker's to form the Junkers-Fokker Aktiengesellschaft on 20 October 1917. The J.I's pattern of an armored fuselage that protected the nose-mounted engine, pilot, and observer in a unitized metal "bathtub" was the possible inspiration^{[citation needed]} for Sergey Ilyushin's later Il-2 Shturmovik (conceivably appropriate as Junkers did have a manufacturing plant in Fili, a suburb of Moscow, in the Soviet Union in the 1920s) with a similar armored fuselage design. As this design philosophy for such combat aircraft had proven to be a good idea, it was once again broadly reused for the 1970s-premiered American Fairchild Republic A-10 Thunderbolt II "Warthog" twin-turbofan powered attack aircraft, also having its pilot enveloped in an armoured titanium bathtub. By 1918, Junkers' firm, with its previously demonstrated preference for monoplane-pattern airframe designs, had created the world's first production low-winged, single-seat monoplane all-metal fighter aircraft, the Junkers D.I, which pioneered the use of Alfred Wilm's 1906 invention of duralumin throughout a production airframe. The D.I did not enter production until 1918. He also produced a two-seat monoplane fighter, the Junkers CL.I. Both postwar Soviet aviation pioneer Andrei Tupolev and American aviation designer William Bushnell Stout owed much to Hugo Junkers in the designs of their earlier aircraft, which benefited from Junkers' corrugated, light-metal construction technique.

The Junkers F.13 of 1919 was the first of several successful civil aircraft designs produced by Junkers Flugzeugwerke: later designs include the Junkers Ju 52/3m from 1932. Through a variety of business initiatives, Junkers was active in founding and developing airlines around the globe, initially intending to sell them aircraft. Airlines where Junkers played a pivotal role in early phases of their development include Deutsche Luft Hansa and Lloyd Aéreo Boliviano. Several business ventures failed from wider economic or political problems that hampered sound engineering plans. Junkers always had more ideas: the massive four-engined G.38, nicknamed "Der Grosse Dessauer", delivered to Luft Hansa, made no commercial trips for many months as he repeatedly recalled it to the factory for improvements.

When the Nazis gained control of the German government in 1933, Junkers opposed their goal of re-armament. They responded by demanding ownership of all patents and market shares from his remaining companies, under threat of imprisonment on the charge of high treason. He was placed under house arrest in 1934 and died on 3 February 1935.

Legacy

Hugo Junkers is mainly known in connection with aircraft bearing his name. These include some he reluctantly developed for the German Empire during World War I, later in minor association with Anthony Fokker, as well as civil aircraft designs during the "interwar period" produced by Junkers Flugzeugwerke (Junkers Aircraft Works). Junkers died in 1935, on his 76th birthday.

The earliest all-metal post-World War I aircraft designs of both Andrei Tupolev — with his Tupolev ANT-2 two-passenger small aircraft of 1924 — and William Bushnell Stout's initial all-metal design, the Stout ST twin-engine torpedo bomber of 1922, were both based directly on the pioneering work of Junkers, with each engineer (one Soviet, one American) separately developing examples of aircraft like Tupolev's enormous, 63 meter wingspan, eight-engined Maksim Gorki — the largest aircraft built anywhere in the world in the early 1930s — and Stout's popular Ford Trimotor airliner.

In 1976, Junkers was inducted into the International Air & Space Hall of Fame.

Junkers was featured in the 2013 semi-fictional movie ''The Wind Rises'' by Japanese director Hayao Miyazaki.

Timeline