The GE9X engine for the Boeing 777X aircraft will feature fewer and thinner composite fan blades than any GE widebody engine in service.

Aircraft engines have traditionally been the domain of metal but aero engine manufacturers are now saving substantial weight by using composites in the fan blades and containment case.

Advances in carbon fibre composites

GE Aviation's first carbon fibre composite fan blade entered commercial service on the GE90 engine in 1995.

The GEnx engine (used on the Boeing 787 Dreamliner) took the technology to the next level with more efficient fan blade designs, a reduced fan blade count (18 blades) and a composite fan case.

The GE9X engine features a 133-inch diameter composite fan case and 16 composite fan blades.

"It has been a decade since GE designed a new composite fan blade for the GEnx engine," says Bill Millhaem, general manager of the GE90/GE9X engine programmes.

"Carbon fibre composite material has advanced in those 10 years, and the advancements enable GE engineers to design a thinner GE9X blade, which is just as strong as our current composite fan blades. 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."

The new material incorporates a higher stiffness carbon fibre and a new epoxy resin. The leading edge material will also be modified from titanium to a steel alloy to further enhance the blade's strength.


Last year, GE saw positive results from material testing on full-sized GEnx blades. Testing of the new material continues in preparation for next year's testing on the new GE9X blade design.

GE engineers continue to work the final design of the GE9X fan blade that will incorporate improved aerodynamics.

Engine certification is scheduled for 2018.

IHI Corporation, Snecma and Techspace Aero (Safran) and MTU Aero Engines AG are also part of the GE9X engine programme.

  • Almost 700 GE9X engines have been ordered by customers since it was launched on the Boeing 777X aircraft last year. Production of the 777X is set to begin in 2017, with first delivery targeted for 2020.