Last Sunday I did a commercial for a friend about 20 miles away. I flew manually never turning on the gps. When I came home I flew again, when I turned on the gps the heli went up and dropped very fast about 2-3 ft. I tried it several time and the same thing happened. When I landed a gust of wind knocked the heli over on two motors. After checking for damage I took it up again and this is what happened. It twitches and won't stay stable. Any thought to what might be wrong. SM