Results of the Aeronautics Research Mission Directorate Seedling Project Phase I research project entitled \“Nonlinear Aerodynamics Modeling using Fuzzy Logic\” are presented. Efficient and rapid flight test capabilities were developed for estimating highly nonlinear models of airplane aerodynamics over a large flight envelope. Results showed that the flight maneuvers developed, used in conjunction with the fuzzy-logic system identification algorithms, produced very good model fits of the data, with no model structure inputs required, for flight conditions ranging from cruise to departure and spin conditions.