Devon and I went to fly some kites we made a few weeks ago. Our kites didn't fly very well, but they did fly. They were not aerodynamically stable and went crazy whenever they were in the air. Actually this made it more fun since it required a lot of interaction from the flier to keep the kite in the air. I think our longest flight was about 30 seconds. I now realize the flaw in the design and am sure I could make a better one if I try again.
While building the kites, I was a little concerned about strength so I built mine with a thicker vertical dowel than Devon choose. It turned out the thicker dowel wasn't necessary, but checking the dowel for flaws and flexibility would have been a good idea. The thinner dowel kite never broke, but on the third crash my thicker dowel snapped into three pieces. I looked at the dowel and the wood grain wasn't perfectly parallel and the dowel snapped easily.
It was great fun!