“With the GE9X we’re continuing that strategy, but we are reaching into the technology cupboard and pulling out new things from the 9X technology pool,” says Millhaem. As well as improved aerodynamics in the compressor and turbine, the project aims to leverage advances in materials, such as next-generation powder metal alloys and ceramic matrix composites, to help bridge the gap between the GEnx and Boeing’s performance goal for the 777X.

“If we start with a scaled GEnx-1B, we get about half-way to what Boeing is asking us to do for the 777X,” Millhaem says. The 777X is targeting fuel burn that is about 10% lower than that of the current GE90-115B-powered 777, while maintaining existing maintenance costs.

Other work is focused on a fourth-generation fan that will operate at higher speed than the current engine. “We’re also going to thinner blades, which allows us to take weight out,” Millhaem adds. Exact details about the structure of the new blade have not been finalized.