page_title: History of the jet engine
section_title: Pre World War II
hierarchical_section_title: History of the jet engine / Pre World War II
caption_attribution_description: English: A picture of a sectioned de Havilland Goblin II describing the internal components. Français&#160;: Photo annotée en anglais d'un de Havilland Goblin en coupe.
context_page_description: Jet engines can be dated back to the invention of the aeolipile around 150 BC. This device used steam power directed through two nozzles so as to cause a sphere to spin rapidly on its axis. So far as is known, it was not used for supplying mechanical power, and the potential practical applications of this invention were not recognized. It was simply considered a curiosity.
  Archytas, the founder of mathematical mechanics, as described in the writings of Aulus Gellius five centuries after him, was reputed to have designed and built the first artificial, self-propelled flying device. This device was a bird-shaped model propelled by a jet of what was probably steam, said to have actually flown some 200 meters.
  Ottoman Lagari Hasan Çelebi is said to have taken off in 1633 with what was described to be a cone-shaped rocket and then to have glided with wings into a successful landing, winning a position in the Ottoman army. However, this was essentially a stunt. The problem was that rockets are simply too inefficient at low speeds to be useful for general aviation.
  The first working pulsejet was patented in 1906 by Russian engineer V.V. Karavodin, who completed a working model in 1907.
context_section_description: In 1928, RAF College Cranwell cadet  Frank Whittle formally submitted his ideas for a turbo-jet to his superiors. In October 1929, he developed his ideas further. On 16 January 1930 in England, Whittle submitted his first patent (granted in 1932). The patent showed a two-stage axial compressor feeding a single-sided centrifugal compressor. Practical axial compressors were made possible by ideas from A.A. Griffith in a seminal paper in 1926 ("An Aerodynamic Theory of Turbine Design"). Whittle would later concentrate on the simpler centrifugal compressor only, for a variety of practical reasons. Whittle had his first engine running in April 1937. It was liquid-fuelled, and included a self-contained fuel pump. Whittle's team experienced near-panic when the engine would not stop, accelerating even after the fuel was switched off. It turned out that fuel had leaked into the engine and accumulated in pools. 
  In 1935, Hans von Ohain started work on a similar design in Germany, and it is often claimed that he was unaware of Whittle's work. Ohain said that he had not read Whittle's patent, and Whittle believed him (Frank Whittle 1907–1996). However, the Whittle patent was in German libraries, and Whittle's son had suspicions that Ohain had read or heard of it.
  Years later, it was admitted by von Ohain in his biography  that this was so. Author Margaret Conner states ″Ohain's patent attorney happened upon a Whittle patent in the years that the von Ohain patents were being formulated". Von Ohain himself is quoted as saying "We felt that it looked like a patent of an idea" "We thought that it was not seriously being worked on." As Ohain's patent was not filed until 1935, this admission clearly shows that he had read Whittle's patent and had even critiqued it in some detail prior to filing his own patent and some 2 years before his own engine ran.
  VON OHAIN: ″Our patent claims had to be narrowed in comparison to Whittle’s because Whittle showed certain things." "When I saw Whittle's patent, I was almost convinced that it had something to do with boundary layer suction combinations. It had a two-flow, dual entrance flow radial flow compressor that looked monstrous from an engine point of view. Its flow reversal looked to us to be an undesirable thing but it turned out that it wasn't so bad after although it gave some minor instability problems.″
  His first device was strictly experimental and could only run under external power but he was able to demonstrate the basic concept. Ohain was then introduced to Ernst Heinkel, one of the larger aircraft industrialists of the day, who immediately saw the promise of the design. Heinkel had recently purchased the Hirth engine company, and Ohain and his master machinist Max Hahn were set up there as a new division of the Hirth company. They had their first HeS 1 centrifugal engine running by September 1937. Unlike Whittle's design, Ohain used hydrogen as fuel, supplied under external pressure. Their subsequent designs culminated in the gasoline-fuelled HeS 3 of 1,100 lbf (5 kN), which was fitted to Heinkel's simple and compact He 178 airframe and flown by Erich Warsitz in the early morning of 27 August 1939, from Rostock-Marienehe aerodrome, an impressively short time for development. The He 178 was the world's first turbojet-powered aircraft to fly.
  The world's first turboprop was the Jendrassik Cs-1 designed by the Hungarian mechanical engineer György Jendrassik. It was produced and tested in the Ganz factory in Budapest between 1938 and 1942. It was planned to fit to the Varga RMI-1 X/H twin-engined reconnaissance bomber designed by László Varga in 1940 but the program was cancelled. Jendrassik had also designed a small-scale 75 kW turboprop in 1937.
  Whittle's engine was starting to look useful and his Power Jets Ltd. started receiving Air Ministry money. In 1941, a flyable version of the engine called the W.1, capable of 1000 lbf (4 kN) of thrust, was fitted to the Gloster E28/39 airframe specially built for it and first flew on 15 May 1941 at RAF Cranwell.
  British aircraft engine designer, F
caption: A picture of an early centrifugal engine (DH Goblin II) sectioned to show its internal components.
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