The EFW N-20 Aiguillon (in English: "Stinger") was Switzerland's first indigenous jet fighter project. The Swiss Federal Aircraft Factory developed a design for a four-engined swept winged fighter following the end of the Second World War. An unpowered sub-scale N-20.01 glider and a turbojet powered test aircraft, also sub-scale and known as the N-20.02 Arbalète ("Crossbow"), were test flown. A fighter prototype N-20.10 Aiguillon was built but never flown, and a twin-engines N.20.20 Harpon was also proposed but not followed up.
The aircraft was to be powered by four turbofan engines buried in the wings, with the bypass air feeding cold-air tunnels each side of the engines including a combustion chamber where additional thrust could be gained. The bypass air could be deflected though large slots on the upper and lower wings to act as aerodynamic flaps or thrust reversers. Two engines could be shut down in flight to increase range. It was planned that the N-20 would carry its armament in a detachable weapons bay, capable of carrying large loads of cannons, rockets or bombs.[1]
SM-1 engine on display
It was initially planned that the aircraft's engines would be designed and built in Switzerland by Sulzer. Sulzer only built a turbojet though, the Sulzer D-45, with a thrust of 7.38kN (1,660lbf). Of these engines, D-45.01 was used in a test rig between 1950 and 1951 and the second engine, D-45.04 (of limited airworthiness) was used until 1955 in a test rig. The D45.04 is part of the Dübendorf museum N-20 display. For the development of the bypass-engine DZ-45 Sulzer expected a development contract worth 10 million swiss francs that never materialized.[2]
The Armstrong Siddeley Mambaturboprop was then chosen as the basis for the N-20's prototype engines, with the propeller reduction gear replaced by a low pressure compressor.[3] This powerplant was named Swiss Mamba SM-1; the conversion was carried out in 1948 by EFW, with only six engines built (four fitted to the N-20 with two spares). One of the spare engines is today part of the Swiss Museum of Transport, at the Flieger-Flab-Museum Dübendorf. Flight tests of the engine began in October 1952 under a De Havilland Mosquito. The proposed development into the SM-5 for the production aircraft was very similar to the DZ-45 proposed by Sulzer in 1947.[4]
EFW N-20.01
Since Swiss industry still had no experience with the aircraft and aerodynamics of jet aircraft, several wind tunnel models were produced. In addition, a 3/5th scale wooden glider, the EFW N-20.01 was built to allow testing of the novel wing shape; this flew on 17 April 1948.[1] The aircraft was equipped with a JATO solid rocket motor, which was able to be started independently to reach the necessary altitude for tests. The nose gear came from a de Havilland Vampire and the main landing gear from a Messerschmitt Bf 109; both were electromechanical retractable. The body was made from wood and fabric covered. The N-20.01 was destroyed in a landing accident on 1 July 1949 at Emmen air force base.
EFW N-20.02 Arbalète
N-20.02 Arbalète on display
The glider had successfully proven the design and was followed by a similar sized powered test aircraft, the EFW N-20.02 Arbalète ("Crossbow"), powered by four 0.98kN (220lbf) Turboméca Piméné turbojets mounted above and below the wings. This aircraft first flew on 16 November 1951. It proved to have good manoeuvrability and reached a maximum speed of 750km/h (466mph).[5]
EFW N-20.10 Aiguillon
The full scale aircraft was estimated to have a maximum speed of 1,095km/h (680mph),[1] but the initial converted Mamba, the SM-1, which was test-flown under a de Havilland Mosquito in 1948 and was the first turbofan to fly,[citation needed] did not generate adequate thrust. Considerable further work was required for the definitive two-shaft SM-5 engine, which was meant to generate 14.7kN (3,300lbf) thrust. The prototype was completed in 1952 and, fitted with four SM-1 engines, flew briefly during a taxi test on 8 April 1952 but development of the engine and the N-20 aircraft was cancelled soon afterwards.[3]
EFW N-20.20 Harpon
During testing it was discovered that the engines would not produce the required thrust, so the N-20.20 project was started. The aircraft was similar to the N-20.10, but had one conventional engine, a Rolls-Royce Avon or Armstrong Siddeley Sapphire turbojet in each wing root. The wing was a little thinner and the main landing gear came a little closer to the fuselage because now there was no need to place the engines within the wing. The N 20:20 was never completed, although some wind tunnel models were manufactured.[6]
Buttler, Tony and Jean-Louis Delezenne. X-Planes of Europe: Secret Research Aircraft from the Golden Age 1946-1974. Manchester, UK: Hikoki Publications, 2012. ISBN978-1-902-10921-3
Haller, Ullrich. "The Swiss N-20 Jet Fighter-Bomber". Air Pictorial, July 1964. pp.203–4.
A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a combination of references to the preceding generation engine technology of the turbojet and the additional fan stage. It consists of a gas turbine engine which achieves mechanical energy from combustion, and a ducted fan that uses the mechanical energy from the gas turbine to force air rearwards. Thus, whereas all the air taken in by a turbojet passes through the combustion chamber and turbines, in a turbofan some of that air bypasses these components. A turbofan thus can be thought of as a turbojet being used to drive a ducted fan, with both of these contributing to the thrust.
An afterburner is an additional combustion component used on some jet engines, mostly those on military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, takeoff, and combat. The afterburning process injects additional fuel into a combustor in the jet pipe behind the turbine, "reheating" the exhaust gas. Afterburning significantly increases thrust as an alternative to using a bigger engine with its attendant weight penalty, but at the cost of increased fuel consumption which limits its use to short periods. This aircraft application of "reheat" contrasts with the meaning and implementation of "reheat" applicable to gas turbines driving electrical generators and which reduces fuel consumption.
The Pratt & Whitney TF30 is a military low-bypass turbofan engine originally designed by Pratt & Whitney for the subsonic F6D Missileer fleet defense fighter, but this project was cancelled. It was later adapted with an afterburner for supersonic designs, and in this form it was the world's first production afterburning turbofan, going on to power the F-111 and the F-14A Tomcat, as well as being used in early versions of the A-7 Corsair II without an afterburner. First flight of the TF30 was in 1964 and production continued until 1986.
The Pratt & Whitney J57 is an axial-flow turbojet engine developed by Pratt & Whitney in the early 1950s. The J57 was the first 10,000 lbf (45 kN) thrust class engine in the United States. It is a two spool engine.
The Armstrong Siddeley Mamba was a British turboprop engine produced by Armstrong Siddeley in the late 1940s and 1950s, producing around 1,500 effective horsepower (1,100 kW).
This article outlines the important developments in the history of the development of the air-breathing (duct) jet engine. Although the most common type, the gas turbine powered jet engine, was certainly a 20th-century invention, many of the needed advances in theory and technology leading to this invention were made well before this time.
The de Havilland Ghost was the de Havilland Engine Company's second design of a turbojet engine to enter production and the world's first gas turbine engine to enter airline service. The Ghost powered the de Havilland Venom, de Havilland Comet and SAAB 29 Tunnan. It was a scaled-up development of the Goblin.
The Heinkel HeS 011 or Heinkel-Hirth 109-011(HeS - Heinkel Strahltriebwerke) was an advanced World War II jet engine built by Heinkel-Hirth. It featured a unique compressor arrangement, starting with a low-compression impeller in the intake, followed by a "diagonal" stage similar to a centrifugal compressor, and then a three-stage axial compressor. Many of the German jet-powered aircraft being designed near the end of the war were designed to use the HeS 011, but the engine itself was not ready for production before the war ended in Europe and only small numbers of prototypes were produced.
The General Electric/Allison J33 is an American centrifugal-flow jet engine, a development of the General Electric J31, enlarged to produce significantly greater thrust, starting at 4,000 lbf (18 kN) and ending at 4,600 lbf (20 kN) with an additional low-altitude boost to 5,400 lbf (24 kN) with water-alcohol injection.
The Vought F6U Pirate was the Vought company's first jet fighter, designed for the United States Navy during the mid-1940s. Although pioneering the use of turbojet power as the first naval fighter with an afterburner and composite material construction, the aircraft proved to be underpowered and was judged unsuitable for combat. None were ever issued to operational squadrons and they were relegated to development, training, and test roles before they were withdrawn from service in 1950.
The Heinkel HeS 3 was the world's first operational jet engine to power an aircraft. Designed by Hans von Ohain while working at Heinkel, the engine first flew as the primary power of the Heinkel He 178, piloted by Erich Warsitz on 27 August 1939. Although successful, the engine had too little thrust to be really useful, and work started on the more powerful Heinkel HeS 8 as their first production design.
The FFA P-16 is a Swiss prototype ground attack jet fighter designed and produced by aircraft manufacturer Flug- und Fahrzeugwerke Altenrhein (FFA). It was Switzerland's second attempt to develop a domestically designed and manufactured jet fighter, following the EFW N-20.
The Arsenal VG 70 was a single-seat monoplane research aircraft flown in France shortly after World War II to assist in the development of high-speed jet fighters. Lacking an indigenous turbojet engine, the aircraft was fitted with a German Junkers Jumo 004. Unlike most jet-powered aircraft of the period, the swept wing was wooden as was the tail structure. The under-powered VG 70 made its maiden flight in 1948, but only flew five times before the program was terminated the following year.
The Vickers Type 559 was a supersonic interceptor aircraft design by the British aircraft company Vickers-Armstrongs and was their submission for Operational Requirement F.155 in 1955.
The Folland Midge was a small, swept-wing British subsonic light fighter aircraft prototype originally developed as a concept demonstrator for the successful Folland Gnat.
The Westinghouse J46 is an afterburning turbojet engine developed by the Westinghouse Aviation Gas Turbine Division for the United States Navy in the 1950s. It was primarily employed in powering the Convair F2Y Sea Dart and Vought F7U Cutlass. The engine also powered the land speed-record car known as the Wingfoot Express, designed by Walt Arfons and Tom Green It was intended to power the F3D-3, an improved, swept-wing variant of the Douglas F3D Skyknight, although this airframe was never built.
The Brandner E-300 was an Egyptian turbojet engine, developed for the Helwan HA-300 light jet fighter.
The Turbomeca Piméné was a small French turbojet engine produced by Turbomeca in the early 1950s.
The ALR Piranha was an aircraft project undertaken by the Swiss Air Force's Swiss Working Group for Aerospace (ALR) to develop a lightweight multi-role combat aircraft with canard wings. The ALR is the Aerospace Project Development Group of the Swiss Air Force. The project was managed by Georges Bridel, an engineer at the ETH Zurich.
Militärflugplatz Emmen is a military airfield of the Swiss Air Force north of Emmen, Switzerland, located northwest of Lucerne.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
