The General Electric GEnx is a turbofan family used on the Boeing 787 Dreamliner and Boeing 747-8. Its two principal branches are the GEnx-1B for the 787 and GEnx-2B for the 747-8. Although they share a family name and important technologies, their dimensions and internal configurations differ.[1]GEnx EngineGE Aerospace · geaerospace.com · Accessed 2026-09-13Open source details
Development approach
GE based the programme on experience gained with the GE90 while introducing new approaches to weight reduction, combustion and compressor aerodynamics. At the 2009 Paris Air Show, GE presented the GEnx as a combination of established architecture and new component technology. This approach linked the programme to an existing large-engine lineage without making it simply a smaller interchangeable GE90.[2]GE's GEnx Engine Unveiled at Paris Air ShowGE Aerospace · ge.com · Accessed 2026-09-13Open source details
The development description emphasised efficiency and durability together. Improved turbine geometry, materials and coatings accompanied the new fan and combustor. These changes addressed several different sources of engine performance: how effectively the machinery compresses and expands air, how much the components weigh, and how the combustion system mixes fuel with air.[2]GE's GEnx Engine Unveiled at Paris Air ShowGE Aerospace · ge.com · Accessed 2026-09-13Open source details
Fan and combustion technology
Carbon-fibre composite fan blades and a composite fan case reduce the weight of the front module. GE lists 18 fan blades, compared with 22 on the earlier GE90 design. Its product description also identifies titanium-aluminide blades in the rear stages of the low-pressure turbine as another means of reducing rotating-system weight.[1]GEnx EngineGE Aerospace · geaerospace.com · Accessed 2026-09-13Open source details
The TAPS combustion approach mixes fuel and air before burning, producing a leaner mixture and reducing the high-temperature conditions that promote nitrogen-oxide formation. GE's development account explains this mechanism separately from fuel-consumption improvements: lower emissions of one pollutant are not a direct substitute for measuring the amount of fuel used.[2]GE's GEnx Engine Unveiled at Paris Air ShowGE Aerospace · ge.com · Accessed 2026-09-13Open source details
Aircraft-specific versions
The GEnx-1B and -2B were tailored to different airframes. GE's comparison gives the -1B a 111.1-inch fan and the -2B a 104.7-inch fan. It also lists four booster stages and seven low-pressure turbine stages for the -1B, versus three and six respectively for the -2B. These differences show why specifications should always identify the version being discussed.[1]GEnx EngineGE Aerospace · geaerospace.com · Accessed 2026-09-13Open source details
Significance
The programme brought composite structures and a lean-combustion system together in a large commercial engine family. Its technical interest lies in that combination and in the adaptation of related machinery to both a twin-engine airliner and a four-engine passenger or freight aircraft, rather than in a single rating that could represent every installation.[2]GE's GEnx Engine Unveiled at Paris Air ShowGE Aerospace · ge.com · Accessed 2026-09-13Open source details[1]GEnx EngineGE Aerospace · geaerospace.com · Accessed 2026-09-13Open source details