The Optimal Control Model (OCM) for manually controlled systems is suggested as an aid to the design of manned flight simulation experiments. The structure of the OCM, and procedures for selecting operator-related model parameters, are reviewed. Applications of the model to the design of specific simulation experiments are summarized. Good correspondence between pre-experiment model predictions and experimental performance trends is shown, demonstrating the utility of the model in the design of simulator tasks that fall within the domain of model application. Examples presented include whole-body and tactile motion cuing, visual scene cuing, and aircraft handling qualities.