Back on thread. I once had close to 18,000 ft in a Ka-8 glider (steel tube and fabric with wooden wings) in wave over the Grampians. I remember it was cold and a rather humbling experience. Part of me loved the sensation of the smooth, elevator-like climb along the wave bar, the feeling of remoteness and the beauty of being able to see most of the country but another part of me kept thinking about the two bolts holding the wings on. Strange really, no difference in likelihood of the wings coming off at 2000' against 200'. I suppose it was just the feeling of being so small against the panorama below me and the power of nature lifting me at about 500' min. That flight was over twenty years ago and I still reflect on it.