Composite fan blades boost aircraft fuel efficiency

GE is utilising a next generation carbon fibre composite for the fan blades of its new GE9X engine, which it says will deliver fuel savings of around 5%.

Due to enter service in 2020, the new lightweight blades will debut in Boeing's upcoming 777X passenger aircraft. "Fewer, thinner blades will enhance the airflow and make for a lighter, more efficient fan that will help with the GE9X engine's overall performance and fuel burn," said Tod Davis, who led the design. The fourth generation of composite material has a stiffer fibre, which means the blades can be crafted at thicknesses much closer to metal versions. The blades' leading edges, formerly made of titanium, will now be made of a new steel alloy to enhance the component's strength. "We thoroughly tested the material at various levels from coupon testing of static, fatigue, and fracture toughness properties to component testing of fatigue and ultimate strength capability," Davis said. "These test results have allowed us to select the best material for the GE9X engine." More than 700 GE9X engines have been ordered so far. The GE team says it is continuing to refine the machine's design to optimise its aerodynamics before the design is frozen in late 2015. Flight testing is expected to begin in 2017.