With the advent of real-time interactive combat simulation on the Advanced Simulator for Pilot Training (ASPT), a requirement for determining weapon effectiveness against moving threats was established. Traditional methods either required an excessive amount of computer memory or were restricted to low fidelity approximations. An innovative approach to this problem was developed for ASPT. An iterative approach utilizing both an aerodynamic model, based upon the weapon ballistics, and the threat position time history serves as a framework for this method. An exact determination of weapon impact or miss can be made through the use of kinetics and calculus. This method allows real-time interactive scenarios that include evasive maneuvers and ECM tactics, yet requires very little computer memory and execution time. This capability is essential for effective and realistic combat simulation.