The hardware and software technology for simulators and flight training devices have advanced enormously over the past ten years. We have been able to create very realistic visual scenes with high resolution, brightness and field of view; motion systems that provide the cues that give the feeling of actually flying in the airplane; high fidelity sounds that represent the operating environment inside the airplane; and computers that are capable of mathematically modeling the equations that represent the various components and systems being simulated. The quality of the data that is used to mechanize the flight dynamics and systems of the airplane being simulated is lagging. This paper focuses on the traditional approach for generating simulator design and verification data, and then describes a flight test approach for improving the quality of the data. Data developed by the traditional approach are compared with data developed by the flight test approach. Comparisons are made of simulated versus flight test results for operational maneuvers, one employing traditional data and the other employing flight test generated data. The need for high quality flight test data that exceeds those of current Development Test and Evaluation (DT&E) and Operational Test and Evaluation (OT&E) results is emphasized.