In the ever-expanding world of unmanned flight, smaller, less expensive UAVs are being used for everything from search and rescue to military operations. In such situations, the working airspace can become crowded and pose a danger to the UAVs themselves. To prevent collisions, the A* search algorithm can be used to dynamically plan paths. We will discuss the A* algorithm, its previous uses in path planning, and how it is being used for dynamic collision avoidance.