Abstract:

ESDU PERF RT 1/3 illustrates, through a worked example, the correction of flight measured range and fuel flow data to conditions of aircraft weight, engine speed and atmosphere different from those at the time of test. Based on the relationship developed in ESDU PERF RT 1/0 two graphs are required. One plots range multiplied by relative density against equivalent airspeed divided by root relative density and jet pipe temperature divided by root relative temperature, and the second plots fuel flow divided by relative density times root relative temperature against engine speed and jet pipe temperature each divided by relative temperature. Although jet pipe temperature is used here it could equally have been turbine inlet temperature or propeller pitch angle. All those values have to be obtained at one value of weight divided by relative pressure to which each graph then applies.