A method for autonomous safe emergency landing of a powered unmanned aerial vehicle in the event of an engine failure, the method comprising the procedures of: generating a landing approach trajectory, comprising: a downwind leg, initiating at an initiation point of said trajectory; an upwind leg, terminating at a selected touchdown point; and a U-turn leg, joining between said downwind leg and said upwind leg; directing said UAV to said initiation point to follow said downwind leg of said landing approach trajectory; repeatedly determining a glide ratio of said UAV, based on current flight conditions of said UAV; repeatedly determining a current turning point (670A, 670B, 670C) along said downwind leg for landing said UAV at said selected touchdown point, said U-turn leg (640A, 640B, 640C) initiating at said current turning point (670A, 670B, 670C), wherein the determination of said current turning point is based on the determined glide ratio and is performed each time with respect to a precedingly determined turning point; repeatedly determining a touchdown point (680A, 680B, 680C) corresponding to said current turning point (670A, 670B, 670C), based on said determined glide ratio, wherein said procedure of determining a current turning point is further performed with respect to the discrepancy between: (i) the touchdown point that was precedingly determined in correspondence with the precedingly determined turning point, and (ii) said selected touchdown point; and when said UAV arrives at said current turning point (670A, 670B, 670C), directing said UAV to follow said U-turn leg and said upwind leg of said landing approach trajectory, for landing said UAV at said selected touchdown point. generating a landing approach trajectory, comprising: a downwind leg, initiating at an initiation point of said trajectory; an upwind leg, terminating at a selected touchdown point; and a U-turn leg, joining between said downwind leg and said upwind leg; a downwind leg, initiating at an initiation point of said trajectory; an upwind leg, terminating at a selected touchdown point; and a U-turn leg, joining between said downwind leg and said upwind leg; directing said UAV to said initiation point to follow said downwind leg of said landing approach trajectory; repeatedly determining a glide ratio of said UAV, based on current flight conditions of said UAV; repeatedly determining a current turning point (670A, 670B, 670C) along said downwind leg for landing said UAV at said selected touchdown point, said U-turn leg (640A, 640B, 640C) initiating at said current turning point (670A, 670B, 670C), wherein the determination of said current turning point is based on the determined glide ratio and is performed each time with respect to a precedingly determined turning point; repeatedly determining a touchdown point (680A, 680B, 680C) corresponding to said current turning point (670A, 670B, 670C), based on said determined glide ratio, wherein said procedure of determining a current turning point is further performed with respect to the discrepancy between: (i) the touchdown point that was precedingly determined in correspondence with the precedingly determined turning point, and (ii) said selected touchdown point; and when said UAV arrives at said current turning point (670A, 670B, 670C), directing said UAV to follow said U-turn leg and said upwind leg of said landing approach trajectory, for landing said UAV at said selected touchdown point.