February 26, 2015
EVENDALE, OHIO -- GE Aviation is celebrating the 20th anniversary of the first jet engine to certify with composite fan blades. Powering an early model of Boeing’s 777 aircraft, the first GE90 engine certified in February 1995—and thus marked the first aviation use of the revolutionary composite fiber polymeric material on a jet engine’s front fan blade.
In the 1980s, GE Aviation gained experience with composite fan blades on its experimental GE36 open rotor jet engine that successfully ground-tested and flew. This bolstered GE to use composite fan blades for the GE90 engine, which required a lightweight, durable material solution for the engine’s large front fan.
GE’s bet on composite fan blades for the GE90 has paid off. For one, the composite blade is critical to the GE90’s record thrust. And the highly-popular GE90-powered 777s are among the most fuel-efficient and reliable commercial jetliners in history. With more than 2,000 GE90 engines delivered, the composite fan blade has become a landmark technology for GE and has influenced succeeding generations of GE commercial engines, including the GEnx and the new GE9X.
But achieving certification of that first composite fan blade was no easy feat. GE Aviation encountered challenges in the design, certification and manufacturing of these unique three-dimensional fan blades.
“For our engineers, one of the biggest hurdles for the composite fan blade was understanding the characteristics of the new carbon fiber material,” said Nick Kray, a consulting engineer for composite design at GE Aviation. “GE conducted hundreds of intensive tests on the new composite material to determine its breaking points. The results gave us enormous confidence in the composite material’s durability.”
For certification, GE worked extensively with Boeing, the U.S. Federal Aviation Administration and customers to educate them on the attributes of carbon fiber composite material. This information sharing paved the way for engine certification.
To manufacture the composite fan blade, GE teamed up with Snecma of France to create CFAN in 1993 located in San Marcos, Texas.
“CFAN has really perfected the production process for composite fan blades,” said Kray. “At the start of production, the yield rate for composite fan blade was less than 30 percent. Today, CFAN has a yield of greater than 97 percent, and the business has doubled its fan blade production in the last five years from 5,000 blades in 2009 to 14,000 fan blades last year.”
For the 128-inch fan diameter on the latest GE90-115B for the Boeing 777-300ER, 777-200LR and the 777 Freighter, GE designed a second-generation composite fan blade using three-dimensional aerodynamic computer design tools. The Museum of Modern Art (MOMA) in New York recognized the uniquely curved design of the GE90-115B composite fan blade as a work of art, and the fan blade is part of MOMA’s Architecture and Design collection.
GE engineers further advanced the design of composite fan blades for the GEnx engine, allowing for a reduced number of blades per fan system (22 blades in the GE90 to 18 blades in the GEnx). The GEnx also utilized carbon fiber composites for the fan case to reduce the engine’s weight by close to 400 pounds.
The next-generation GE90 engine, the GE9X, will feature fewer and thinner composite fan blades than any GE widebody engine in service. To do this, GE is designing a new composite fan blade using next-generation carbon fiber composite material. The GE9X will have just 16 fan blades on its 134 inch front fan. The fewer, thinner blades will enhance the engine’s airflow and make for a lighter, more efficient fan that will help with the GE9X’s overall performance and fuel burn.
The GE9X engine will be in the 100,000 pound thrust class. Along with the composite fan system, key features of the GE9X 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 carbon matrix composite (CMC) material in the combustor and turbine.
Almost 700 GE9X engines have been ordered by customers since it was launched on the Boeing 777X aircraft last year.
The first engine will test in 2016 with flight-testing on GE’s flying testbed anticipated in 2017. Engine certification is scheduled for 2018.
IHI Corporation, Snecma and Techspace Aero (Safran), and MTU Aero Engines AG are participants in the GE9X engine program.
Click HERE to learn how CFAN, a joint venture between GE Aviation and Snecma, manufactures composite fan blades for the GE90 and GEnx engines. To learn more about GE Aviation’s use of composite material, click here.
GE Aviation, an operating unit of GE (NYSE: GE), is a world-leading provider of jet and turboprop engines, components and integrated systems for commercial and military aircraft.