The goal of this work has been to develop a design suggestion of a visualization system that supports training instructors and air force units during After Action Reviews (AAR) in training at the Swedish Air Force Combat Simulation Center (FLSC). The suggestion was developed through a design study consisting of interviews, a demonstration and a design workshop in parallel with an iterative prototyping process. The study resulted in a visualization system that indicates enemy aircraft at threatening distances to support identification of critical situations. To support the following threat assessment, visualizations that automatically present radar lock-on information and missile envelopes are suggested. Although radar lock-on information and missile envelopes has been presented in earlier visualizations they have not been adapted to the mode of operations of the AAR. Adapting the visualizations to the AAR would make the threat assessment easier and more effective to conduct. The purpose of the visualization is to make it easier for training instructors and air force units with limited experience of simulation training to conduct a high quality AAR through emphasizing relevant situations and points of interest.