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.
The Pratt & Whitney F100 is a low bypass 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 F-15 Eagle. The engine was to be developed in tandem with the F401 which shares a similar core but with an upscaled fan for the U.S. Navy's F-14 Tomcat. The F401 was later abandoned due to costs and reliability issues. The F100 also powered the F-16 Fighting Falcon for the Air Force's Lightweight Fighter (LWF) program.
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 Lyulka AL-21 is an axial flow turbojet engine created by the Soviet Design Bureau named for its chief designer Arkhip Lyulka.
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 license by several other companies worldwide. Among its major uses was the Lockheed F-104 Starfighter, Convair B-58 Hustler, McDonnell Douglas F-4 Phantom II, North American A-5 Vigilante and IAI Kfir.
The Pratt & Whitney J75 is an axial-flow turbojet engine first flown in 1955. A two-spool design in the 17,000 lbf (76 kN) thrust class, the J75 was essentially the bigger brother of the Pratt & Whitney J57 (JT3C). It was known in civilian service as the JT4A, and in a variety of stationary roles as the GG4 and FT4.
The General Electric/Allison J35 was the United States Air Force's first axial-flow compressor jet engine. Originally developed by General Electric in parallel with the Whittle-based centrifugal-flow J33, the J35 was a fairly simple turbojet, consisting of an eleven-stage axial-flow compressor and a single-stage turbine. With the afterburner, which most models carried, it produced a thrust of 7,400 lbf (33 kN).
The Pratt & Whitney J52 is an axial-flow dual-spool turbojet engine originally designed for the United States Navy, in the 40 kN class. It powered the A-6 Intruder and the AGM-28 Hound Dog cruise missile. As of 2021 the engine was still in use in models of the A-4 Skyhawk.
The General Electric J85 is a small single-shaft turbojet engine. Military versions produce up to 3,500 lbf (16 kN) of thrust dry; afterburning variants can reach up to 5,000 lbf (22 kN). The engine, depending upon additional equipment and specific model, weighs from 300 to 500 pounds. It is one of GE's most successful and longest in service military jet engines, with the civilian versions having logged over 16.5 million hours of operation. The United States Air Force plans to continue using the J85 in aircraft through 2040. Civilian models, known as the CJ610, are similar but supplied without an afterburner and are identical to non-afterburning J85 variants, while the CF700 adds a rear-mounted fan for improved fuel economy.
The Snecma M88 is a French afterburning turbofan engine developed by Snecma for the Dassault Rafale fighter.
The Tumansky R-13 is a Soviet turbojet engine designed by Sergei Alekseevich Gavrilov.
The Tumansky R-25 is a turbojet engine, which is seen as the ultimate development of Tumansky R-11. It was designed under the leadership of Sergei Alekseevich Gavrilov.
The Lyulka AL-7 was a turbojet designed by Arkhip Mikhailovich Lyulka and produced by his Lyulka design bureau. The engine was produced between 1954 and 1970.
The Tumansky RD-9 was an early Soviet turbojet engine, not based on pre-existing German or British designs. The AM-5, developed by scaling down the AM-3, was available in 1952 and completed testing in 1953; it produced 25.5 kN (5,700 lbf) thrust without afterburner. The AM-5 engine is notable for making possible the first mass-produced supersonic interceptors such as the MiG-19, and the first Soviet all-weather area interceptor, the Yak-25. When Sergei Tumansky replaced Alexander Mikulin as the OKB-24's chief designer in 1956, the engine was renamed RD-9. The engine was later built under license in China as the WP-6.
The Pratt & Whitney PW1120 turbojet is a derivative of the F100 turbofan. It was installed as a modification to a single F-4E fighter jet, and powered the canceled IAI Lavi.
The General Electric YJ93 turbojet engine was designed as the powerplant for both the North American XB-70 Valkyrie bomber and the North American XF-108 Rapier interceptor. The YJ93 was a single-shaft axial-flow turbojet with a variable-stator compressor and a fully variable convergent/divergent exhaust nozzle. The maximum sea-level thrust was 28,800 lbf (128 kN).
The Westinghouse J34, company designation Westinghouse 24C, was a turbojet engine developed by Westinghouse Aviation Gas Turbine Division in the late 1940s. Essentially an enlarged version of the earlier Westinghouse J30, the J34 produced 3,000 pounds of thrust, twice as much as the J30. Later models produced as much as 4,900 lb with the addition of an afterburner. It first flew in 1947. The J46 engine was developed as a larger, more powerful version of Westinghouse's J34 engine, about 50% larger.
The General Electric J73 turbojet was developed by General Electric from the earlier J47 engine. Its original USAF designation was J47-21, but with innovative features including variable inlet guide vanes, double-shell combustor case, and 50% greater airflow was redesignated J73. Its only operational use was in the North American F-86H.
The Volvo RM8 is a low-bypass afterburning turbofan jet engine developed for the Saab 37 Viggen fighter. An augmented bypass engine was required to give both better fuel consumption at cruise speeds and higher thrust boosting for its short take-off requirement than would be possible using a turbojet. In 1962, the civil Pratt & Whitney JT8D engine, as used for airliners such as the Boeing 727, was chosen as the only engine available which could be modified to meet the Viggen requirements. The RM8 was a licensed-built version of the JT8D, but extensively modified for supersonic speeds, with a Swedish-designed afterburner, and was produced by Svenska Flygmotor.
The General Electric J97 is a single-shaft turbojet engine designed and built by General Electric as a compact high-performance engine for light attack fighters and eventually a number of drone projects.
