This is my dad's plane of choice and we have had several instances where the plane just goes crazy. It seems like it always happens on the second flight (?) The plane starts to porpoise almost vertically. When it happens, you have almost no control at all. We have totalled this plane 5 or 6 times and I will say it is a tough design and easy to fix. Definitely an issue with the SAFE system. Enough so that we jokingly wrote "UN"safe on the side with a sharpee.