I know what you mean. I was spotting for a friend as he was flying a 2 meter glider. We saw it enter a low cloud and never saw it come out. He liked flying underneath clouds as he said that was where the lift was. I think it was a House-of-Balsa plane. I put a new radio into my Bird of Time and launched it on a high start. When it came off the high start, I realized the controls were backwards. It dove to the ground, went inverted, crossed the field and disappeared in an area the park had just cut down with very high brush piles. We never found the plane, neither did the park as they would return anything they found to us. One of the huge piles had bones at the bottom and a distinct growling sound coming from inside.