Textron Aviation has opted for GE Aviation’s all-new turboprop engine to power its single engine turboprop (SETP). The 1300 shaft horsepower (SHP)-rated turboprop engine will be the first entry in GE’s new family of turboprop engines designed specifically for business and general aviation aircraft in the 850- to 1600-SHP range.
Brad Mottier, Vice President and General Manager of GE Aviation's Business & General Aviation and Integrated Systems division, said during the recent announcement that “this new engine features an industry-best 16:1 overall pressure ratio (OPR), enabling the engine to achieve up to 20% less fuel consumption and 10% more cruise power compared to competitor offerings in the same size class, which usually feature an OPR of 9:1. It also has 4000-6000 hour MTBO,” or mean time between overhauls, which is about 30% longer than with existing engines.
As an advantage of being part of GE, says Mottier, “We don’t have to pay for research, we just go to the GE store for proven technologies from GE’s large commercial and military engines and props. For example, we didn’t have to pay hundreds of millions of dollars into research for stator vanes.”
Other new design and manufacturing technologies leveraged from GE’s latest military and commercial engines include an all-titanium, 3D aero compressor design for lightweight and efficient power generation and additive manufacturing capabilities pioneered for the CFM LEAP turbofan.
“For the past five years, GE conducted design studies and actively researched the turboprop market to identify and integrate the best of our next-gen commercial and military technologies at the lowest cost and risk to our business aviation customers,” said Mottier. “Our mission is to make the operation of this engine look just like a jet.”
“Our SETP will combine the best of both clean-sheet aircraft and new engine designs,” said Christi Tannahill, Senior Vice President, Turboprops and Interior Design at Textron Aviation. “We expect it to outperform the competition in critical areas ranging from cabin size and acquisition cost to performance capability and fuel savings.”
Textron Aviation’s new aircraft is expected to have a range of more than 1500 nmi and speeds higher than 280 knot. Part of the enablers to those statistics are key features of the new turboprop engine that include a ruggedized, modular architecture based on the T700/CT7 turboshaft, and cooled turbine blades that enable higher thrust and fuel efficiency, also leveraged via technology from the T700/CT7. In the latter case, multi-stage turbines take air out of the compressors to cool the blades.
The engine also features integrated electronic propulsion control for optimized single-lever engine and propeller control. The new engine could be retrofit on older aircraft, though there would have to be changes in the cockpit to accommodate it. There's no official word yet on whether the propellers for the engine are being designed and sourced from GE's Dowty.
There is no prototype of the engine running today, though GE expects to conduct the detailed design review (DDR) for the new turboprop in 2017 followed by the first full engine test in 2018, for which the company has dedicated about 200 engineers, according to Mottier. It is expected to weigh about 535 lb.
Continued development, testing, and production of the new turboprop engine will occur at GE Aviation’s new turboprop Center of Excellence in Europe, announced this past September. The new facility will represent an investment exceeding $400 million and ultimately support 500-1000 new jobs. “All the engine systems will be integrated outside of the U.S.” said Mottier.
GE Aviation is combining the expertise gained from its Walter Engine turboprop facility in the Czech Republic with its other military and commercial jet engine technologies in its quest to pursue additional turboprop engines. GE research continues on a new 5000-SHP turboprop engine for the regional market that will leverage GE’s new GE38 turboshaft military helicopter engine (for the U.S. Marines’ CH53-K heavy lift helicopter), as well as technologies across GE’s more broad jet engine portfolio.
GE Aviation claims to have the largest development engine portfolio in the jet propulsion industry and invests more than $2 billion annually in research and development. GE employes 8000 engines, with about 3000 outside of the U.S., said Mottier.