It happened to me! I started out with what I thought was a typical calibration dance before takeoff, hit the motor start, and immediately had a full power flyaway straight up. The bird climbed to maybe 100' before I pulled both joysticks full down. The motors stopped at altitude with the bird crashing down (fortunately!) onto the metal roof of my shop. I have absolutely NO idea what caused this as I had maybe 50 successful flights prior, as well as maybe 15 on a friend's P2. Damage to the shell, mainly metal threaded tie plates and nuts that came loose from the molding. I bought a new shell kit, as well as a whole new receiver board because the antenna wire end shells came loose, one lost.