 The D-27's three-shaft gas turbine engine has an axial low-pressure compressor, a mixed-flow high-pressure compressor, an annular combustion chamber, a single-stage high-pressure turbine, and a single-stage low-pressure turbine.The SV-27 contra-rotating propfan, provided by SPE Aerosila, is driven by a four-stage turbine via a shaft connected to a planetary reduction gear which incorporates a thrust meter.The eight-bladed front propeller receives most of the engine power output and provides most of the thrust, while the back propeller has only six blades.