Three types of ground-based simulators of the X-22A aircraft are evaluated and compared with actual flight. Simulator types employed were a fixed-base simulator with linearized equations of motion, a fixed-base simulator with nonlinearized equations of motion, and a moving-base simulator with linearized equations of motion. Evaluations are based on comparisons of pilot ratings, pilot comments, and dynamic response time history data. Data comparisons are interpreted and discussed in terms of significant factors such as simulator type, complexity, and physical and psychological cues. Several correlations among the different simulators and flight are developed in terms of numerical pilot ratings of specific flight conditions and tasks. These pilot rating correlations provide a basis for projecting flight characteristics from results obtained with the simulator types evaluated. Relative capabilities and limitations of the various simulators to represent flight and minimum standards of adequacy for specific tasks are also established for hover and transition. (Author).