Several years back our club had a "build and fly" event. We were in teams of 3-4 people each, got a "kit" of some balsa sheets & sticks, I believe a foam wing core, a little ply, and an engine/mount / radio (or we brought our own "donor" radio & servos, etc, don't remember).

Each team got about 3 hours, maybe 4 to "design", build, and have ready for flight an airplane. Then there were events designed to test them - both aerodynamically and structurally. I think the winner was the one with the last flyable airplane..

Anyway - it was a lot of fun!