Scientists at the Air Force Research Laboratory's Warfighter Training Research Division in Mesa, AZ are engaged in a basic research program to advance the state of the art in computational process models of human performance in complex, dynamic environments. Current modeling efforts are focused on developing and validating a fine-grained cognitive process model of the Uninhabited Aerial Vehicle (UAV) operator. The model is implemented in the ACT-R cognitive modeling architecture. The design of the model is inspired by the well-known "Control and Performance Concept" in aviation. The study described here was conducted in order to assess how accurately the model represents the information processing activities of expert pilots as they are flying basic maneuvers with a UAV simulation. The data suggest: (a) pilots verbalize attention to performance instruments more often than control instruments, despite the fact that they generally appear to be using the control and performance concept to fly these maneuvers, (b) the distribution of operator attention across instruments is influenced by the goals and requirements of the maneuver, and (c) although the model is an excellent approximation to the average proficiency level of expert aviators, for an even better match to the process data, the model should be extended to include the use of trim and a meta-cognitive awareness of the passage of time.