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Aircelle's exhaust systems will equip the 777X's two GE Aviation GE9X turbofan engines, providing the benefits of lower mass, along with increased resistance to heat with the use of Aircelle processes for titanium high-temperature applications. These exhaust systems are among the largest of their type ever produced for civil aircraft, and include acoustically treated areas for a reduced noise level signature. (Aircelle: Patrick Boule)

Ground testing begins on the GE9X

In mid April, ground testing began on the first full GE9X development engine at GE Aviation’s Peebles Testing Operation in Ohio. The GE9X engine will power Boeing’s new 777X aircraft. According to Bill Millhaem, General Manager of the GE90/GE9X engine programs at GE Aviation, “The ground testing will generate data on the full engine system and aerodynamic performance, mechanical verification, and aero thermal system validation.”

Maturation testing of the GE9X turbofan engine began about five years ago and has progressed from component-level all the way to the recent first full engine to test (FETT). FETT brings all the GE9X technologies together to demonstrate their operability as a complete propulsion system.

The GE9X FETT began just six months after the engine's design was finalized, which is much earlier in the development process compared to most other engine programs. GE says this timing assures that everything learned from FETT will be captured in the certification engines. Next year will see the GE9X program starting certification testing and flight testing on GE Aviation’s flying test bed. Engine certification is anticipated in 2018.

IHI Corporation, Snecma and Techspace Aero (Safran), and MTU Aero Engines AG are just a few of the participants in the GE9X engine program

Another Safran company, Aircelle, is supplying titanium engine exhaust systems for the 777X, marking its first major role as a supplier to Boeing. The exhaust system is being used as part of the overall engine development program in partnership with Boeing and GE. These exhaust systems are among the largest of their type ever produced for civil aircraft, and include acoustical treatment areas, also of titanium, for a reduced noise level signature.

The exhaust systems on the two GE9X engines offer both mass efficiencies and increased resistance to heat primarily as a result of Aircelle's processes for titanium high-temperature applications. Aircelle has optimized the design and manufacturing of titanium nacelle components, applying its expertise and proprietary database in defining and validating the metal's performance for exhaust systems. The company has invested in new and upgraded production resources for the 777X program, while also working with Boeing in ensuring routines and procedures are fully compliant with its production requirements.

With almost 700 GE9X engines on order, the GE9X engine will be in the 100,000-lb thrust class and will have a large front fan 134-in in diameter with a composite fan case and 16 fourth-generation carbon fiber composite fan blades. Other key features include a next-generation 27:1 pressure-ratio 11-stage high-pressure compressor; a third-generation TAPS III combustor for high efficiency and low emissions; and CMC material in the combustor and turbine.

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