Considering that direct and reliable measurement of high pressure turbine inlet temperature on board is not feasible at present

a new assembled method for estimation of turbofan engine high pressure turbine inlet temperature was proposed. Based on the energy conservation principles of a turbofan engine

thermodynamic equations between high pressure turbine inlet temperature and other gas path parameters were presented

thus six estimation models of high pressure turbine inlet temperature were derived. Unmeasured parameters of these models were defined as temperature model coefficients as a whole

which were fitted with measured engine power setting parameters using an engine performance model. Validation results show that assembled estimation models have good precision for both health and deteriorative engines

and the mean squared error of its best performance model is not above 1%. Moreover

by comparison with linear and neural network fitting methods

the assembled estimation method has a clear advantage in precision and stability.