Five Game

Nov 16, 2023

The top five engine families of the 20th century.

From piston engines to turbojets and high bypass turbofans, aircraft engines have come a long way in pushing the limits of propulsive efficiency. Among many state-of-the-art engines, here is a list of the top five engines that revolutionized the world of aviation.

First introduced in 1948, the Rolls-Royce Dart is a turboprop engine that combines the power of jet propulsion with the efficiency of propellers. The engine was widely used in the first generation of turboprop-powered aircraft, including the Dutch Fokker F-27 and British Vickers Viscount.

With a two-stage centrifugal compressor, seven straight-flow combustion chambers, and a three-stage axial turbine, the engine produced 1,354 kW of power, rotating at approximately 15,000 RPM. The Dart enabled much lower operating costs than its predecessors with greater speed and comfort. The engine remained in production for nearly forty years until the last Fokker F27 Friendships and Hawker Siddeley HS 748s were produced in 1987.

The PW JT3 entered commercial service with the Boeing 707 jetliner in 1958. The commercial variant of the US Air Force’s J53 engine, the JT3 revolutionized the jet age of commercial aircraft. The engine featured a 9-stage low-pressure (LP) compressor, a 7-stage high-pressure (HP) compressor, and a cannular-type combustor. The all-axial turbine featured a single HP turbine and a two-stage LP turbine.

The engine was modified into a low bypass turbofan engine, the JT3D, in the early 1960s. The first three compressor stages were replaced with two fan stages, which extended beyond the compressor casing to act like propellers. The resulting increase in airflow lowered fuel consumption, noise, and emissions. JT3Ds became widely used, especially on long-range Boeing 707-300s and Douglas DC-8s.

The General Electric CF6 is a family of high-bypass turbofan engines powering a wide variety of commercial airliners. First used on the Douglas DC-10s, the initial CF6 featured a single-stage fan with one core booster stage, driven by a 5-stage LP turbine. Within the HP system, a 16-stage HP axial compressor was driven by a two-stage HP turbine.

The engine had a theoretical bypass ratio of 6, hence the name CF6. Generating an airflow of 1,300 lbs/second through the fan, the resulting relative bypass ratio was 5.72. The CF6 provided a static thrust of 41,500 lb (185.05 kN). The high bypass of the GE engine represented a historic breakthrough in fuel efficiency.

From the Airbus A300 to Boeing's 767, 747, and the Lockheed C-5M Super Galaxy, CF6 applications are diverse. By 2018, GE has delivered more than 8,300 CF6 engines (-6s, -50s, -80Cs, -80Es, and LM6000 industrial gas turbines).

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The CFM International (a joint venture between General Electric and Safran Aircraft Engines) CFM56 series is a family of high-bypass turbofan engines with a thrust range of 18,500 to 34,000 lbf. GE produces the HP compressor, combustor, and HP turbine, while Safran manufactures the fan, gearbox, exhaust, and LP turbine.

CFM56 engines are the most used turbofan aircraft engines in the world. In recent times, CFM56 variants power two of the most modern narrowbody jets, the Airbus A320 family and the Boeing 737 (Classics and NGs). Nearly 33,000 engines were built between 1974 and 2018; hence the family being the world's most successful.

The Rolls-Royce Trent is a family of high-bypass turbofan engines with unique three-spool architecture and thrust ranging from 61,900 to 97,000 lbf (275 to 431 kN). The first variant, Trent 700, was introduced to the market in 1995 with the Airbus A330 widebody aircraft.

Many other variants followed, such as the following:

What are your thoughts about the top five aircraft engines that shaped commercial air travel in the 20th century? Tell us in the comments section.

Writer - Omar is an aviation enthusiast who holds a Ph.D. in Aerospace Engineering. With numerous years of technical and research experience under his belt, Omar aims to focus on research-based aviation practices. Apart from work, Omar has a passion for traveling, visiting aviation sites, and plane spotting. Based in Vancouver, Canada