As far as I know, the Corvair Cruiser is the first airplane expressly designed to fly with corvair power. The Pietenpol was the first airplane to be fitted with a Corvair by it's designer, but the original engine was a Ford model A. The Corvair Cruiser is a pretty little plane too -- I'm a sucker for V-tails. Oh! and the design is put together from flat sheets of composites; so it's very similar to a paper card model in design, so I like that as well.