EXTENDED RANGE OPERATIONS OF 2 AND 3 TURBOFAN ENGINED AIRPLANES

The objective of the present work is a comparative analysis of the beh avior of two and three turbofan engined airplanes after engine failure . A simple but fairly realistic treatment of the range equation allows study of extended range operations of airplanes after any prescribed decrease in thrust. The approach takes into account the increase in pa rasite drag, and considers variations of thrust and specific fuel cons umption with altitude and Mach number. All peculiarities of the powerp lant are translated into a few nondimensional parameters. The model pr ovides the long-range cruise conditions after engine failure, namely a ltitude and Mach number, and the additional fuel needed to reach the f inal destination. Results for a typical 5000-km route show the relativ e disadvantage of twins.