Was flying my drone over country area when a small object appeared center screen of video and flew past the drone to the left side of video. the object covered 1/2 mile in 3 second, so it was moving at an accelerated speed. there is a main overhead power line that runs behind the property. the object was flying parallel to them at approximately the same height. the object was travelling west to north west in an exact straight parallel line consistent with the overhead power lines. the object was only viewed for a few seconds in the video before exiting the view of the drone camera. object appears to move to fast for a bird. seems to me, by the math, the object had to be moving at 300 to 500 mph to cover that distance it accomplished in the video.