GE Aviation revealed plans on Monday at NBAA 2016 to incorporate more additive manufacturing, widely known as 3-D printing, in future engines, among them the Advanced Turboprop (ATP) slated to power the Cessna Denali.
Brad Mottier, GE Aviation’s vice president for business aviation and integrated systems, said the push into more additive content will reduce cost and weight, while improving reliability. It will also dramatically reduce the time it takes to design and manufacture engine components and significantly reduce overall parts counts.
GE is already using a limited number of printed parts on production airliner engines, such as the fuel nozzles on the CFM Leap and the T25 sensor housing on the GE90. A research team reduced 900 parts on a GE CT7 turboshaft to 16 printed parts, achieving a 35-percent weight reduction and making the engine more efficient. The exercise took 18 months. Mottier said it would be conservative to assume that the cost of manufacturing a legacy engine could be reduced by 20 percent using additive methods.
“For us, the goal is to create whatever we can imagine," said Mohammad Ehteshami, vice president of GE Additive. Ehteshami said printing technology has not been applied to rotating parts—yet—but this is definitely in future plans. “It’s not too far off,” he said. Parts “printed” to date have mainly been composed of aircraft aluminum, titanium and cobalt chrome.
GE has spent $1 billion on additive manufacturing initiatives so far and is focusing on obtaining faster and better machines, Mottier said. However, even with current technology, the time saving over traditional manufacturing techniques is dramatic.
Ehteshami said parts that typically take six to eight months to design and fabricate take only a month using additive techniques. On the ATP, GE plans to replace 855 parts with 12 manufactured additively. Mottier said the unique modifications GE makes to its machines combined with the proprietary nature of materials composition and parts coding would make unauthorized parts manufacture difficult.
In addition to the ATP, GE's other engine programs continue to make progress. The Passport 20 turbofan for the Bombardier Global 7000 has logged 2,800 test hours and 3,900 cycles, and test articles have been delivered. GE estimates the engine will have logged 4,000 hours and 8,000 cycles by entry into service.
GE also reports that fully half of all CF34 turbofans are now enrolled in the OnPoint hourly maintenance program, marking 200-percent enrollment growth since 2010. All of GE’s business aircraft engines can now be supported through an online app downloadable from the Apple App Store or Google Play. Finally, GE reported that the single-lever electronic engine power controller it developed for the Nextant G90XT outfitted with GE H75 engines is nearing certification.