The General Electric J79 is an

axial-flow An axial compressor is a gas compressor that can continuously pressurize gases. It is a rotating, airfoil-based compressor in which the gas or working fluid principally flows parallel to the axis of rotation, or axially. This differs from other ...

turbojet The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and ...

engine built for use in a variety of fighter and

bomber aircraft A bomber is a military combat aircraft that utilizes air-to-ground weaponry to drop bombs, launch torpedoes, or deploy air-launched cruise missiles. There are two major classifications of bomber: strategic and tactical. Strategic bombing is d ...

and a supersonic

cruise missile A cruise missile is an unmanned self-propelled guided missile that sustains flight through aerodynamic lift for most of its flight path. Cruise missiles are designed to deliver a large payload over long distances with high precision. Modern cru ...

. The J79 was produced by

General Electric Aircraft Engines General Electric Company, doing business as GE Aerospace, is an American aircraft engine supplier that is headquartered in Evendale, Ohio, outside Cincinnati. It is the legal successor to the original General Electric Company founded in 1892, w ...

in the United States, and under license by several other companies worldwide. Among its major uses was the

Lockheed F-104 Starfighter The Lockheed F-104 Starfighter is an American single-engine, supersonic interceptor. Created as a day fighter by Lockheed as one of the " Century Series" of fighter aircraft for the United States Air Force (USAF), it was developed into an ...

Convair B-58 Hustler The Convair B-58 Hustler, designed and produced by American aircraft manufacturer Convair, was the first operational bomber capable of Mach 2 flight. The B-58 was developed during the 1950s for the United States Air Force (USAF) Strategic Air ...

McDonnell Douglas F-4 Phantom II The McDonnell Douglas F-4 Phantom II is an American tandem two-seat, twin-engine, all-weather, long-range supersonic jet interceptor and fighter-bomber that was developed by McDonnell Aircraft for the United States Navy.Swanborough and Bower ...

North American A-5 Vigilante The North American A-5 Vigilante is an American carrier-based supersonic bomber designed and built by North American Aviation (NAA) for the United States Navy. Before the 1962 unification of Navy and Air Force designations, it was designated A3 ...

and

IAI Kfir The Israel Aircraft Industries Kfir (, "Lion Cub") is an Israeli all-weather multirole combat aircraft based on the French Dassault Mirage 5, with Israeli avionics and an Israeli-built version of the General Electric J79 turbojet engine. Develop ...

. A commercial version, designated the CJ805, powered the

Convair 880 The Convair 880 is a retired American Narrow-body aircraft, narrow-body jet airliner produced by the Convair division of General Dynamics. It was designed to compete with the Boeing 707 and Douglas DC-8 by being smaller but faster, a niche that f ...

, while an aft-turbofan derivative, the CJ805-23, powered the

Convair 990 The Convair 990 Coronado is a retired American narrow-body four-engined jet airliner produced between 1961 and 1963 by the Convair division of American company General Dynamics. It was a stretched version of its earlier Convair 880 produced in ...

airliners and a single

Sud Aviation Caravelle The Sud Aviation SE 210 Caravelle is a French jet airliner produced by Sud Aviation. It was developed by SNCASE in the early 1950s, and made its maiden flight on May 27, 1955. It included some de Havilland designs and components developed for t ...

intended to demonstrate to the U.S. market the benefits of a bypass engine over the existing

Rolls-Royce Avon The Rolls-Royce Avon was the first axial flow jet engine designed and produced by Rolls-Royce. Introduced in 1950, the engine went on to become one of their most successful post-World War II engine designs. It was used in a wide variety of ai ...

turbojet. In 1959 the gas generator of the J79 was developed as a stationary 10 MW-class ()

free-turbine turboshaft A free-turbine turboshaft is a form of turboshaft or turboprop gas turbine engine where the power is extracted from the exhaust stream of a gas turbine by an independent turbine, downstream of the gas turbine. The power turbine is not mechanicall ...

engine for naval power, power generation, and industrial use, called the LM1500. Its first application was in the research

hydrofoil A hydrofoil is a lifting surface, or foil, that operates in water. They are similar in appearance and purpose to aerofoils used by aeroplanes. Boats that use hydrofoil technology are also simply termed hydrofoils. As a hydrofoil craft gains sp ...

Development

Evolution of the variable stator compressor

By the late 1940s, jet engine design had progressed to the point where further progress was limited by the performance of its compressor, in particular the pressure ratio of the compressor had to be increased to reduce the engine fuel consumption. However, the useful operating range of the compressor was limited at that time and centered around its design condition which is at a high compressor speed for take-off or cruise. If designed for high efficiency at high speeds it was very inefficient and prone to stall at low speeds. In 1944 the

National Advisory Committee for Aeronautics The National Advisory Committee for Aeronautics (NACA) was a United States federal agency that was founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its ...

had tested a theory for "Extending the useful operating range of axial-flow compressors by use of adjustable stator blades" by running an eight-stage axial compressor with pressure ratio 3.42:1 and adjustable blade angles. Considerable improvement in efficiencies were obtained at compressor speeds appreciably below the design speed. Departures of velocity from the design condition are most noticeable in the first stages at low rpm and become more so as the design pressure ratio is increased leading to blade stall and compressor surging as happened with the

compressor, with design pressure ratio of 6.3:1 in 1949. In 1947

Geoff Wilde Geoffrey Light Wilde (21 May 1917 – 18 August 2007) was a British engineer employed by Rolls-Royce Limited. Early life Geoffrey Light Wilde was born in Plumstead, London. He was first educated in France, where his father Alfred was working. ...

, a Rolls-Royce compressor designer, had applied for a patent "Axial flow compressor regulation" "to provide a compressor with a wide speed-range of operation". An experimental 12-stage compressor was built with the inlet guide vanes and first four rows of stator blades adjustable to lower the air incidence angles while running at low speed. It was very effective in overcoming the stall and surge. However, a simpler mechanical-design solution (variable inlet guide vanes and bleed) had already been shown to work with the required design pressure ratio so variable stators were not used in a Rolls-Royce engine until the 1980s (

IAE V2500 The IAE V2500 is a two-shaft high-bypass turbofan engine built by International Aero Engines (IAE) which powers the Airbus A320 family, the McDonnell Douglas MD-90, and the Embraer C-390 Millennium. The engine's name is a combination of the ...

). By 1950 General Electric was focussing on supersonic engines with variable stators as a result of design studies which compared them with dual-rotor types. Based on their past experience at that time, and estimation of the development effort required to prove new technologies, variable stators promised the best way of designing the compressor for the high required pressure ratio of 12:1. This pressure ratio was needed to achieve the supersonic performance, subsonic cruise performance and low weight necessary for future supersonic aircraft. In 1951, a General Electric team led by

Gerhard Neumann Gerhard Neumann (October 8, 1917 – November 2, 1997) was a German-American aviation engineer and executive for General Electric's aircraft engine division (which today is called GE Aerospace). Born and raised in Germany, he went to Chin ...

, at that time in charge of engine development testing, was given funding to build a test compressor with variable stators. In addition, the Aircraft Gas Turbine Division lead, C.W. 'Jim' LaPierre, formed two teams to do design studies for an engine that could run for extended periods at Mach 2.0 while still giving good fuel economy while cruising at Mach 0.9. Neumann led a team using a variable stator configuration, while Chapman Walker led a parallel effort using two-spools. After a years study the engine with variable stators was chosen as it was lighter, simpler and had a smaller diameter. A demonstrator engine with variable stators, the GOL-1590, predecessor to the J79 was built. At the same time a new engine, the X-24A, was designed for a supersonic aircraft and selected by the Air Force. Development of the new engine was supported by running the GOL-1590 demonstrator engine.

General

GE won the Air Force contract for a new engine with approximately , with afterburning, to power a new supersonic bomber, which became the

. The two other engines offered by GE, an advanced version of the existing J73 and a much larger design, known as the J77, were both cancelled. The first prototype of the production version, XJ-79, ran on 8 June 1954. The first flight of the engine was on 20 May 1955 with the engine installed in a

General Electric J47 The General Electric J47 turbojet (GE company designation TG-190) was developed by General Electric from its earlier J35. It first flew in May 1948. The J47 was the first axial-flow turbojet approved for commercial use in the United States. It ...

-powered

North American B-45C Tornado The North American B-45 Tornado is an early American jet bomber designed and manufactured by aircraft company North American Aviation. It has the distinction of being the first operational jet bomber to enter service with the United States Air ...

''(''serial 48-009'')''. In flight the J79 was lowered from the bomb bay into the airstream for testing. The first flight after the 50-hour qualification test, required for a new engine that is the sole source of thrust for a flying testbed, was on 8 December 1955, powering the second pre-production

Douglas F4D Skyray The Douglas F4D Skyray (later redesignated F-6 Skyray) is an American carrier-based supersonic fighter/interceptor designed and produced by the Douglas Aircraft Company. It was the first naval fighter to exceed the speed of sound in level fli ...

, with the J79 in place of its original

Westinghouse J40 The Westinghouse J40 was an early high-performance afterburning turbojet engine designed by Westinghouse Aviation Gas Turbine Division starting in 1946 to a US Navy Bureau of Aeronautics (BuAer) request. BuAer intended to use the design in sever ...

engine as part of the General Electric development and qualification program. The YF-104 was the next airplane to fly with the J79 followed by a re-engined

Grumman F11F Tiger The Grumman F11F/F-11 Tiger is a supersonic, single-seat carrier-based fighter aircraft designed and produced by the American aircraft manufacturer Grumman. For a time, it held the world altitude record of , as well as being the first supersonic ...

in a Navy-sponsored program to gain experience with the engine before the first flight of the F4H (F-4). The J79 was used on the F-104 Starfighter, B-58 Hustler, F-4 Phantom II, A-5 Vigilante, IAI Kfir aircraft and the

SSM-N-9 Regulus II The SSM-N-9 Regulus II was a guided supersonic cruise missile armed with a nuclear warhead, intended for launching from surface ships and submarines of the U.S. Navy (USN).Koch, Charles A"Regulus II cruise missile".''Regulus II Cruise Missile''. ...

supersonic cruise missile. It was produced for more than 30 years. Over 17,000 J79s were built in the US, and under license in Belgium, Canada, Germany, Israel, Italy, and Japan. A downgraded version of the

General Dynamics F-16 Fighting Falcon The General Dynamics F-16 Fighting Falcon is an American single-engine supersonic Multirole combat aircraft, multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superio ...

with a J79 was proposed as a low-cost fighter for export, and though a prototype aircraft was flown, it found no customers. The J79 was replaced by the late 1960s in new fighter designs by

afterburning An afterburner (or reheat in British English) is an additional combustion component used on some jet engines, mostly those on military aircraft, military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, ta ...

turbofans such as the

Pratt & Whitney TF30 The Pratt & Whitney TF30 (company designation JTF10A) 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 ...

used in the

F-111 The General Dynamics F-111 Aardvark is a retired supersonic, medium-range, multirole combat aircraft. Production models of the F-111 had roles that included attack (e.g. interdiction), strategic bombing (including nuclear weapons capabilit ...

and

F-14 The Grumman F-14 Tomcat is an American carrier-capable supersonic aircraft, supersonic, twinjet, twin-engine, Tandem#Aviation, tandem two-seat, twin-tail, all-weather-capable variable-sweep wing fighter aircraft. The Tomcat was developed for t ...

, and newer generation

turbofan A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft engine, aircraft propulsion. The word "turbofan" is a combination of references to the preceding generation engine technology of the turbojet and the add ...

s with the

Pratt & Whitney F100 The Pratt & Whitney F100 (company designation JTF22) is a low bypass afterburner, afterburning turbofan engine. It was designed and manufactured by Pratt & Whitney to power the U.S. Air Force's "FX" initiative in 1965, which became the McDonnell ...

used in the

F-15 Eagle The McDonnell Douglas F-15 Eagle is an American twin-engine, all-weather fighter aircraft designed by McDonnell Douglas (now part of Boeing). Following reviews of proposals, the United States Air Force (USAF) selected McDonnell Douglas's des ...

which give better cruise

fuel efficiency Fuel efficiency (or fuel economy) is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical energy, chemical potential energy contained in a carrier (fuel) into kinetic energy or Mechanical work, w ...

by-passing air around the core of the engine. For their part in designing the J79, Gerhard Neumann and Neil Burgess of General Electric Aircraft Engines were jointly awarded the

Collier Trophy The Robert J. Collier Trophy is awarded annually "for the greatest achievement in aeronautics or astronautics in America, with respect to improving the performance, efficiency, and safety of air or space vehicles, the value of which has been t ...

in 1958, also sharing the honor with

Clarence Johnson Clarence Leonard "Kelly" Johnson (February 27, 1910 – December 21, 1990) was an American aeronautical and systems engineer. He is recognized for his contributions to a series of important aircraft designs, most notably the Lockheed U-2 an ...

(Lockheed F-104) and the US Air Force (Flight Records).

Design

The compressor blades and vanes are made of 403

stainless steel Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...

, except for the -3B and -7A variants, which have A286 vanes at stages 7 through 17. The compressor rotor is made of Lapelloy, B5F5 and titanium. The J79 makes a particular howling sound at certain throttle settings. This strange feature led to the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

operated F-104B Starfighter, ''N819NA'', being named ''Howling Howland''.Bashow 1986, p. 16. Early engines also produced noticeable quantities of smoke, especially at mid-throttle/cruise settings, a disadvantage in combat aircraft making them vulnerable to visual detection. Later models were redesigned to be "smokeless". The

turboshaft A turboshaft engine is a form of gas turbine that is optimized to produce shaft horsepower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the ex ...

counterpart to the J79 is the General Electric LM1500, used for land and marine applications. Many J79-derived engines have found uses as gas turbine power generators in remote locations, in applications such as powering pipelines. The J79 has two commercial derivatives: CJ805-3 (a non-afterburning engine, fitted with thrust reverser and sound suppressor), and the CJ805-23 (with a free-wheeling aft fan and thrust reverser) fitted to the Convair CV-880 and the Convair CV-990 respectively. J79 engines may be started using compressed air directly on the engine turbine blades or by using a turbine starter attached to the accessory gearbox. The gas used in this starter is either compressed air or from a solid propellant cartridge.

Variants

General Electric J79-GE-3B engine airflow cutaway

;XJ79-GE-1 :Prototype. First ground static test run on 8 June 1954 produced with afterburner. ;YJ79-GE-1 :Flight test engines were designated YJ79-GE-1. ;J79-GE-2 :Powered the McDonnell F4H-1 Phantom (F-4A), of afterburner thrust. ;J79-GE-2A :Essentially similar to the -2 ;J79-GE-3 :Used in the YF-104A, F-104A and the

Grumman F11F-1F Super Tiger The Grumman F11F-1F Super Tiger (company designation G-98J) is a single-seat fighter aircraft originally developed for the United States Navy (USN). Based on the USN's Grumman F-11 Tiger, F-11 Tiger, the F11F-1F did not proceed beyond the two F11 ...

;J79-GE-3A :YF-104A, F-104A and F-104B. ;J79-GE-3B :F-104A and F-104B. ;J79-GE-5A :

with afterburner. ;J79-GE-5B :Convair B-58 Hustler with afterburner. ;J79-GE-5C ;J79-GE-7 :F-104C, F-104D and F-104F. ;J79-GE-7A :F-104C, F-104D and F-104F. :;J79-OEL-7 ::Licensed production GE-7 manufactured by

Orenda Engines Orenda Engines was a Canadian aircraft engine manufacturer and parts supplier. As part of the earlier Avro Canada conglomerate, which became Hawker Siddeley Canada, they produced a number of military jet engines from the 1950s through the 1970 ...

to power the

Canadair CF-104 The Canadair CF-104 Starfighter (CF-111, CL-90) is a modified version of the Lockheed F-104 Starfighter supersonic fighter aircraft built in Canada by Canadair under licence. It was primarily used as a ground attack aircraft, despite being des ...

. ;J79-GE-8:

and F4H-1 (F-4B) with of afterburner thrust ;J79-GE-8A :Sub-variant of the -8 ;J79-GE-8B :Sub-variant of the -8 ;J79-GE-10 :F-4J, of afterburner thrust. ;J79-GE-11 : ;J79-GE-11A :German F-104G and TF-104G. Pakistani

Griffin The griffin, griffon, or gryphon (; Classical Latin: ''gryps'' or ''grypus''; Late and Medieval Latin: ''gryphes'', ''grypho'' etc.; Old French: ''griffon'') is a -4; we might wonder whether there's a point at which it's appropriate to talk ...

F-104A and F-104B. with afterburner. Many -11 engines were licensed manufactured in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

as part of the large F-104

consortium A consortium () is an association of two or more individuals, companies, organizations, or governments (or any combination of these entities) with the objective of participating in a common activity or pooling their resources for achieving a ...

production programme,

Alfa Romeo Alfa Romeo Automobiles S.p.A. () is an Italian carmaker known for its sports-oriented vehicles, strong auto racing heritage, and iconic design. Headquartered in Turin, Italy, it is a subsidiary of Stellantis Europe and one of 14 brands of mu ...

Fiat Fiat Automobiles S.p.A., commonly known as simply Fiat ( , ; ), is an Italian automobile manufacturer. It became a part of Fiat Chrysler Automobiles in 2014 and, in 2021, became a subsidiary of Stellantis through its Italian division, Stellant ...

and

Fabrique Nationale , trading as FN Herstal and often referred to as Fabrique Nationale, or simply FN, is a leading firearms manufacturer based in Herstal, Belgium, and former vehicle manufacturer. It was the largest exporter of military small arms in Europe . FN ...

being the main suppliers for the project. :;J79-IHI-11A ::Licensed production GE-11A, built in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Ishikawajima-Harima Heavy Industries Co., Ltd , formerly known as is a Japanese engineering corporation headquartered in Tokyo, Japan that produces and offers ships, space launch vehicles, aircraft engines, marine diesel engines, gas turbines, gas engines, railway systems, turbochargers fo ...

to power their similarly licensed built F-104J and F-104DJ Starfighters. :;J79-MTU-J1K ::Licensed built and improved version of the GE-11A manufactured by

MTU Aero Engines MTU Aero Engines AG is a German aircraft engine manufacturer. MTU develops, manufactures and provides service support for military and civil aircraft engines. MTU Aero Engines was formerly known as MTU München. History While the Munich-based e ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

;J79-GE-15 :F-4C, RF-4C, F-4D; with 17,000 lbf (75.6kN) of afterburner thrust. ;J79-GE-17 :F-4E, RF-4E, F-4EJ, F-4F, F-4G; with of afterburner thrust. ;J79-GE-19 :

Aeritalia F-104S The Aeritalia F-104S Starfighter was a licensed production Italian version of the Lockheed F-104 Starfighter, which served in the Italian Air Force, and was its mainstay from the late 1960s until the beginning of the 21st century. The F-104S als ...

; also retrofitted to F-104As of the 319th FIS. ;J79-GE-J1E :License-built in

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

by Beit Shemesh Engines Ltd. (BSEL) with afterburning thrust for the

. ;J79-GE-119 :F-16/79

Applications

;Aircraft *

* General Dynamics F-16/79 *

Northrop X-21 The Northrop X-21A was an experimental aircraft designed to test wings with laminar flow control. It was based on the Douglas Aircraft Company, Douglas WB-66D airframe, with the wing-mounted engines moved to the rear fuselage and making space for ...

* SSM-N-9/RGM-15 Regulus II ;Land speed record cars *

Art Arfons Arthur Eugene Arfons (February 3, 1926 – December 3, 2007) was the world land speed record holder three times from 1964 to 1965 with his ''Green Monster'' series of jet-powered cars, after a series of ''Green Monster'' piston-engine and j ...

' "Green Monster" *

Craig Breedlove Norman Craig Breedlove Sr. (March 23, 1937 – April 4, 2023) was an American professional race car driver and a five-time world land speed record holder. He was the first person in history to reach , and , using several turbojet-powered vehi ...

's "Spirit of America - Sonic 1" *

North American Eagle Project The North American Eagle Project was a jet powered car that was intended to challenge the (Mach 1.02) land speed record set by the ThrustSSC in 1997. The venture was a collaboration between Canadian and US engineers, pilots, and mechanics. In 2 ...

Specifications (J79-GE-17)

References

Notes

Bibliography

* * Pace, Steve. ''Lockheed F-104 Starfighter''. Osceola, Wisconsin: Motorbooks International, 1992. . * Bashow, David L. ''Starfighter: A Loving Retrospective of the CF-104 Era in Canadian Fighter Aviation, 1961–1986''. Stoney Creek, Ontario: Fortress Publications Inc., 1990. . * Gunston, Bill. ''Fighters of the Fifties''. Cambridge, England. Patrick Stephens Limited, 1981. . * Williams, Nick and Steve Ginter "Douglas F4D Skyray". Simi Valley, California: Ginter, 1986. .

External links

General Electric Aviation, J79 page

Animation of J79 turbojet (German language)
{{USAF system codes

J79 The General Electric J79 is an axial-flow turbojet engine built for use in a variety of fighter and bomber aircraft and a supersonic cruise missile. The J79 was produced by General Electric Aircraft Engines in the United States, and under l ...

1950s turbojet engines