INTRODUCTION

Reduction methods for propeller turbine aircraft are more complicated than for turbo-jet aircraft because at least one additional variable is usually introduced into the performance equations, compared with the case of turbo-jets.

When only one additional variable is introduced, a graphical method of reduction is more practicable than an analytical one, because there is as yet little knowledge of the precise variation of engine performance with the independent parameters. Such a method is presented in the group of Data Items, ESDU PERF RT 1/1, 1/2 and 1/3 (see References 2, 3 and 4), but no attempt has been made to cover the case of a fourth independent variable in the engine performance equations. It should be noted that modifications to the engine controls may be necessary to allow separate control of, for instance, rpm and jet pipe temperature.