This paper aims to propose a waypoint path planning for the forced landing of an unmanned aerial vehicle in an emergency based on the terminal velocity prediction method, in order to satisfy the approach conditions. In the proposed path planning method, a flight path is represented by a set of waypoints and a combination of rectilinear path and curvilinear path. Based on this representation with some approximations, the terminal velocity prediction method is analytically derived. By using the terminal velocity prediction method, the path planning problem can be converted into a problem finding appropriate positions of the waypoints in order to satisfy the approach conditions for a safe landing. Since the problem is given by a nonlinear system of equations, it can be readily solved using a simple numerical method. Compared to other methods, the proposed method can allow to satisfying the approach conditions with a low computational load. Numerical simulation is performed to conduct the performance of the proposed method.