Computer simulations continue to prove to be a valuable tool in physics education. Based on the needs of an Aviation Physics course, we developed the PHYSics of FLIght Simulator (PhysFliS), which numerically solves Newton's second law for an airplane in flight based on standard aerodynamics relationships. The simulation can be used to pique students' interest, teach a number of physics concepts, and teach computational investigation techniques. This paper describes the development and operation of this simulation, illustrates an example study that can be performed using it, and suggests further ideas for its use. (Contains 4 figures.)