Output Error Method and Two Step Method for Aerodynamic Model Identification

The authors describe an instrumentation system, the flight path reconstruction models and the aerodynamic model identification results obtained for a Cessna Citation II jet aircraft, based on actual flight test data. The CL(a) curve obtained for quasi-static environments is compared with a CFD solution that was computed using non-viscous Euler equations for a three-dimensional model of the aircraft, 1 with deviations of 2% and 6% observed for the CLa and CL0 coefficients, respectively. For the dynamic case, the same aerodynamic model structure is studied using two different identification methods: the Output Error Method and the Two Step Method. In both cases only the aircraft longitudinal dynamics are considered. A proof of match performed on a consolidated aerodynamic model showed good prediction capability.