Fixed Wing Autonomous Aerial Vehicles (FW-AAV) face several challenges when surveying an area. One of the most crucial challenges that the vehicle face is to plan and adjust its path according to the obstacles that exist in the area. Although FW-AAV has good capability in conducting forward movement, its maneuverability is limited. It can't pause its movement in a location and it doesn't flexible enough to change its direction significantly when facing obstacles. In a real-world environment, the obstacles could also shift according to the unpredictable situation. In this paper, we propose a dynamic motion planning for an FW-AAV using Greedy Principle. This method tries to direct the FW-AAV path planning movement when facing obstacles considering its maneuver limitation. The proposed method introduces a concept of 4 directional rotatable Distance Sensor. The Greedy Principle is applied by choosing the nearest possible vacant path obtained by the directional sensor. The method is tested in a 3-Dimensional environment, which includes several realworld obstacles that the vehicle faces and a moving target which is the vehicle needs to reach. Using the Greedy principle, the FW-AAV could successfully reach the moving target safely.