ABSTRACT
This chapter introduces three types of aero engines, namely, turboprop, turboshaft, and propfan engines. Both turboprop and turboshaft have their exhaust gases leaving the engine at a very low or nearly zero speeds. Power, rather than thrust, is the key factor in both. Turboprop engines power many heavy transport aircraft flying at moderate subsonic speeds. The turboshaft engines discussed here are limited to helicopters only. Turboshaft engines employed in other applications are treated in Chapter 8 and identified as gas turbines, which are employed in numerous industrial applications. Propfan engines combine many features of both turbofan and turboprop engines, so it is included here. No separate chapter is allocated to propfan engines until now as these have limited applications in the aviation industry.
