Story ID: 362
Serbia's Green Power Certifying Small Turboprop Engine
By: Matt Thurber
Caption: Low-cost turboprop engine could be suitable replacement for pistons
Word Count: 422
Green Power Turbine Systems has unveiled its TPE200 turboprop engine, which the Serbian company expects to be certified by EASA in about a year. The compact engine delivers 260 shp and features a fully digital electronic control designed by Green Power, which was a first-time exhibitor at the MEBAA show in Dubai this week.
There is a market for this kind of engine, according to Goran Memon, project manager for the program and Green Power sister company EDePro (Engine Development and Production). Gasoline-powered piston engines are facing fuel-sourcing problems in many parts of the world, and the aviation industry “is looking to replace piston engines with turboprops,” he said. The easy availability of jet fuel is one factor but so is the improved performance and reliability of turbine engines, he added, “even in small aircraft.” 
The other benefit of small turbine engines is that they could serve a much larger market than just manned aircraft. UAVs need reliable powerplants, and these vehicles are expensive and intended to fly many missions, so engine longevity is important, Memon explained. With a larger market, more engines could be produced, thus lowering costs across a higher volume of engines. 
The TPE200 design is modular, so each major component is more easily accessible for maintenance, and it has a TBO target of 7,000 hours. Airflow is routed from the rear of the engine through a centrifugal compressor with a 6:1 compression ratio, then through an annular combustion chamber with 12 fuel nozzles. The expanding gases drive a single-stage centrifugal turbine and a single-stage axial turbine, which spin a gearbox and the output shaft and propeller. 
Turbine blades are made of relatively ordinary Inconel with no special cooling features, according to Memon. An interesting design feature is the starter-generator, which is mounted to the center shaft at the air inlet. 
Memon is targeting a price of roughly $150,000 to $175,000 for the engine, which would make it an attractive option for light aircraft designers. Green Power is developing a single-engine training airplane as the first to be powered by the TPE200 and this will be followed by a twin-engine airplane. 
Green Power is also designing small turbojet engines and has a few engine sizes running in its development program. The company has been working on these small turbine engines for more than 10 years, according to Nikola Pejić, Green Power business consultant. “Finally everything is coming together,” he said. “It is the heart of the vehicle.”