I had my Phantom 3 Standard Flip one time on takeoff. Come to find out that when I did the CSC to start the motors the right stick was jammed by a piece of debris and did not move ALL the way back to center. When I used the left stick to lift off it flipped. After doing a CSC I now check to make sure both sticks are centered before attempting to liftoff. It was a very very small piece of sand/grit wedged in the control stick that caused that.