Aerodynamic model identification of turboprop aircraft based on flight test data

The aerodynamic model of an aircraft can be considered as a mathematical representation of the forces and moments acting on the aircraft. These forces and moments are usually approximated by polynomials as function of aircraft’s state variables. The coefficients in the polynomials are known as the aerodynamic parameters. These aerodynamic parameters are of importance in the evaluation of aircraft performance and stability-control characteristics of an aircraft. These parameters also can be used in the design of, for example, automatic flight control systems and mathematical model of flight simulator. This paper will discuss the principles of the aerodynamic model identification of the aircraft based on flight test data using parameter identification techniques. The paper starts with discussion of a mathematical model of an aircraft. Next, parameter identification techniques will be described. Two techniques often used for estimation of the aerodynamic parameters will be discussed. Results of the modelling and estimation of the aerodynamic parameters, state trajectory of the aircraft, bias errors in the instrumentation system, and calibration factors of the vane-angle of attack from flight test data of the N-250 turboprop aircraft will be presented in this paper. Original achievement of that paper is the mathematical model of a turboprop aircraft.