The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a portmanteau of "turbine" and "fan": the turbo portion refers to a gas turbine engine which achieves mechanical energy from combustion, and the fan, 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 Rolls-Royce RB.183 Tay is a medium-bypass turbofan engine, developed from the RB.183 Mk 555 Spey core and using a fan scaled directly from the Rolls-Royce RB.211-535E4 to produce versions with a bypass ratio of 3.1:1 or greater. The IP compressor and LP turbine were designed using technology from the RB.211 programme. The engine was first run in August 1984. The Tay 650 had a new HP turbine which incorporated new technology which had been proven with the RB.211-535E4. This engine also had a new combustor for improved durability. The Tay family is used on a number of airliners and larger business jets, including the Gulfstream IV family, Fokker 70 and Fokker 100, with a later version being used to re-engine Boeing 727-100s.
The Pratt & Whitney F119, company designation PW5000, is an afterburning turbofan engine developed by Pratt & Whitney for the Advanced Tactical Fighter (ATF) program, which resulted in the Lockheed Martin F-22 Raptor. The engine delivers thrust in the 35,000 lbf (156 kN) class and was designed for sustained supersonic flight without afterburners, or supercruise. Delivering almost 22% more thrust with 40% fewer parts than its F100 predecessor, the F119 allows the F-22 to achieve supercruise speeds of up to Mach 1.8. The F119's nozzles incorporate thrust vectoring that enable them to direct the engine thrust ±20° in the pitch axis to give the F-22 enhanced maneuverability.
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. The J57/JT3C was developed into the J52 turbojet, the J75/JT4A turbojet, the JT3D/TF33 turbofan, and the XT57 turboprop. The J57 and JT3C saw extensive use on fighter jets, jetliners, and bombers for many decades.
The Rolls-Royce AE 3007 is a turbofan engine produced by Rolls-Royce North America, sharing a common core with the Rolls-Royce T406 and AE 2100. The engine was originally developed by the Allison Engine Company, hence the "AE" in the model number.
The Snecma M88 is a French afterburning turbofan engine developed by Snecma for the Dassault Rafale fighter.
The SNECMA M53 is an afterburning turbofan engine developed for the Dassault Mirage 2000 fighter by Snecma. The engine is in service with different air forces, including the latest Mirage 2000-5 and 2000-9 multirole fighters.
The General Electric TF34 is an American military turbofan engine used on the A-10 Thunderbolt II and S-3 Viking.
The Pratt & Whitney Canada PW300 series is a family of turbofan jet engines developed by Pratt & Whitney Canada specifically for business jet applications.
The Garrett TFE731 is a family of geared turbofan engines commonly used on business jet aircraft. Garrett AiResearch originally designed and built the engine, which due to mergers was later produced by AlliedSignal and now Honeywell Aerospace.
The General Electric GE38 is a gas turbine developed by GE Aviation for turboprop and turboshaft applications. It powers the Sikorsky CH-53K King Stallion as the T408.
The CFE CFE738 is a small turbofan engine aimed at the business/commuter jet market manufactured by the CFE Company, and is used on the Dassault Falcon 2000.
The Honeywell/ITEC F124 is a low-bypass turbofan engine derived from the civilian Honeywell TFE731. The F125 is an afterburning version of the engine. The engine began development in the late 1970s for the Republic of China (Taiwan) Air Force AIDC F-CK Indigenous Defence Fighter (IDF), and it first ran in 1979. The F124/F125 engine has since been proposed for use on other aircraft, such as the T-45 Goshawk and the SEPECAT Jaguar, and currently powers the Aero L-159 Alca and the Alenia Aermacchi M-346. The F124 has a rather unusual design for a two spool gas turbine engine, using both axial and centrifugal compressors in its high-pressure compressor. There are currently only three production variants of the engine, although several more have been proposed throughout its lifespan.
The Honeywell T55 is a turboshaft engine used on American helicopters and fixed-wing aircraft since the 1950s, and in unlimited hydroplanes since the 1980s. As of 2021, more than 6,000 of these engines have been built. It is produced by Honeywell Aerospace, a division of Honeywell based in Phoenix, Arizona, and was originally designed by the Turbine Engine Division of Lycoming Engines in Stratford, Connecticut, as a scaled-up version of the smaller Lycoming T53. The T55 serves as the engine on several major applications including the CH-47-Chinook, the Bell 309, and the Piper PA-48 Enforcer. The T55 also serves as the core of the Lycoming ALF 502 turbofan. Since the T55 was first developed, progressive increases in airflow, overall pressure ratio, and turbine inlet temperature have more than tripled the power output of the engine.
The Honeywell HTF7000 is a turbofan engine produced by Honeywell Aerospace. Rated in the 6,540–7,624 lbf (29.09–33.91 kN) range, the HTF7000 is used on the Bombardier Challenger 300/350, Gulfstream G280 and Embraer Legacy 500/450 and the Cessna Citation Longitude. Its architecture could be extended for a range of 8,000 to 10,000 lbf thrust.
The Garrett TPF351 is a turboprop engine designed by Garrett Engine Division of AlliedSignal Aerospace Company. Initiated by Garrett in October 1987, the TPF351-20 engine was selected by Embraer to power the Embraer/FMA CBA 123 Vector, a high-speed commuter "pusher" aircraft. It was first tested on May 19, 1989 and then ground tested and flight tested on a Boeing 720 on July 9, 1990. The first prototype CBA 123 was tested on July 18, 1990, followed by a flight to the Farnborough Air Show in September of the same year. Both programs were cancelled in 1992, when the TPF351 was nine months from engine certification.
The Turbomeca Astafan is a single-spool, variable-pitch turbofan engine developed from the Turbomeca Astazou. Despite successful flight-testing, an efficient, quiet and clean design and some commercial interest, the Astafan never entered series production. The engines were only flown on the Fouga 90 prototype and Turbomeca's two test aircraft.
The Turbomeca Aspin was a small French turbofan engine produced by Turbomeca in the early 1950s. This geared turbofan design was the first turbofan to fly, powering the Fouga Gemeaux test-bed aircraft on 2 January 1952.
The Honeywell FX5 was a 6,000lb-thrust (27kN) geared turbofan based on a technology demonstrator core. Aiming for a 20%-plus reduction in cost of ownership from the TFE731-60 and to span a 3,000–8,000 lbf (13–36 kN) family, it could have been certificated within 36 months. It was proposed for the Dassault Falcon 7X business jet launched in 2001, but the Pratt & Whitney Canada PW307 was finally selected. The Honeywell range comprises the previous 6,700–7,500 lbf (30–33 kN) Lycoming ALF502/Honeywell LF507 and the subsequent 6,540–7,550 lbf (29.1–33.6 kN) Honeywell HTF7000.
