I was recently playing a game called Glyder2 on my HP Touchpad and was reminded of a book that I read when I was in Junior High in the Mid 80's. It was about a group of people that flew with wings similar to a hang glider. I specifically remember them talking about riding thermals. I believe the main character went on a trip for some reason. The only thing I have been able to find online is about Windhaven. this is not the book that I remember.