The Lark. I had the plans from an old Jetco kit. This version is powered by a Cox .010 engine, and it can also be built as a rubber-powered model. I have flown it at a local football field. The .010 engine is incredibly powerful. After launch, the model climbs gradually for a second or two; then the engine leans out, the it goes into a vertical climb -- it goes up like a bottle rocket. It then settles into a flat, circular glide, and lands on the wheels. Awesome.