Several times, Once I had a problem starting an engine on a 40 size cub I believe it was a K&B .45 anyways after figuring out it was the fuel line, fixed the problem, pointed into the wind and took off lost it after 40 yards or so. Forgot to pull the antenna out. Plane kinda floated around on its own then ended up in the top of a tree.
Direct Connection Tsunami bad cell in the on board pack, lots of altitude full throttle nothing no control, plane dipped a wing and dived straight down.