A number of studies by various helicopter safety organizations have concluded that pilot error in decision-making is a root cause in a significant percentage of helicopter accidents. The studies have also indicated that instruction and practice in critical decision-making is not a part of many helicopter pilot training programs. To address this problem, a project to develop a low-cost simulator for pilot decision training was initiated. The decision training tool is a combination of computer-based simulation, full motion video, still photography, audio, and feedback. For the purpose of developing robust and realistic mission scenarios for the simulation tool, 17 emergency medical service pilots participated in interviews to identify events that require critical decision-making. This paper describes the development of the first mission scenario, formative evaluation, and implementation plans for fielding the decision trainer.