ESDU 70022:1973

The method presented is applicable at subsonic and supersonic speeds to aircraft powered by turbine engines other than propeller turbines, for which data in the RT series are applicable. The non-dimensional groups used are obtained by substituting expressions for thrust and drag, given in ESDU 70020, in the force equation for steady level flight. The limitations of the theory used to derive the expressions for thrust and drag are indicated in ESDU 70020 which also discusses various additional factors (Reynolds number, thrust angle, centre of gravity variation, power plant operation, gravity variation, flight path length, buoyancy) that affect the analysis of measured performance and methods by which they may be taken into account. The worked example presents the complete test results for level speed and specific range for a four-engined jet transport.