Marks Models Windfree Glider
Anyway, I was out in my aunt and uncle's back yard when I looked up and saw what appeared to be a radio controlled airplane flying silently through the sky. At the time, I could only have dreamed of owning a "real" RC plane and radio. In fact, I had very recently purchased a used OS Digital 3-channle remote control system from a man that lived down the road from me, and did not even have an airplane for it. So, I beat feet down the road in search of its pilot. I eventually ended up at the high school, where the guy was standing with his shiny Kraft 2-channel RC system. He said that the Windfree had bee airborne for over 30-minutes when I got there. Once he landed, he popped off the canopy to show me the radio compartment. It had one of those old "brick" combos that combined two servos and the receiver into a single unit. Come to think of it, something like that would be kind of convenient today.
He hooked the Windfree onto his HiStart bungee launcher and off it went again. I was thrilled to personally witness such a spectacle. About a year later, I has saved enough money from my paper route to buy a Marks Models Windward sailplane. Unlike the Windfree which has a 99" wingspan, the Windward had a more modest 72" wingspan.
A few years later I bought a Windfree kit. Just as with the Windfree, it was of very sparse construction and had virtually no strength until the Monokote was applied. It must have been good enough because a lot of people were flying them and winning contests. Mine did not last long with my unrefined flying (mainly landing) skills.
The photo at the right is of Mark Smith holding his contest-winning Windfree glider.
Here is a source for a laser-cut Windfree kit.
Wingspan = 99.25"