In response to a couple recent threads, here's an idea for a fun little toy airplane: Take the dimensions of the Minimax and develop an airplane that uses the same engine and general configuration but with a simplified carbon fiber airframe. Before continuing, let me describe the general benefits of going with carbon: * In terms of dollars per unit strength and stiffness, it is about the same cost as usable wood, cheaper than the equivalent 4130 steel, and much cheaper than either spruce aircraft lumber or aircraft plywood. Now that the A380 is almost done and 787 has peaked, worldwide supply exceeds demand so carbon prices are declining against inflation. Composites salvage firms are once again offering low prices on seconds and overstocks. * Contrary to common opinion, carbon fiber is easy to work with. By mass and person-hour, most of my high-performance sailplanes are built by amateurs in their first or second week of carbon fiber experience. I generally have people making small parts on their second day in the shop. * Carbon fiber and epoxy are easy to ship, much more so than long sticks of lumber or sheets of plywood for which the shipping often exceeds the cost of the materials. * As demonstrated by Dick Schreder's HP-18 and RS-15 kit sailplanes, the judicious combination of pre-molded and field-fabricated parts can result in a simple, lightweight aircraft that is sleek and attractive. * The judicious use of pultruded carbon fiber allows for a lightweight cantilever wing that can be attached and removed in the field by a single person with no tools. Okay, here's a sketch of what I propose: The main element is a molded carbon fiber shell for the forward fuselage tub and cowling that also includes the wing side-of-body fillet. The neat thing about making these as molded composite parts is that they can have a compound curves that smoothly transition from the tapers of the aft fuselage and the wing. These molded parts would really jazz up the aesthetics of the airplane with only a modest increase in expense. The tub would be supplied as raw shells that the builder would join along a joggle, and in which they install simple bulkheads, ring stiffeners, and reinforcements. Most of these structures would be foam shapes that the builder cuts from sheet, glues into place, and skins with carbon fiber. Along the aft edge would be a joggle that the builder attaches to the aft fuselage skins. The aft fuselage would be a carbon fiber shell that the builder would fabricate using simple molding techniques. The builder takes a 4x8 sheet of 0.032" aluminum, curves it to fit into wooden cradles at each of the ends, and uses it as a mold for each of the three aft fuselage skins (right, left, and top). Each skin has simple longerons and ring stiffeners molded into it. Vacuum bagging of the skins is optional. The wings and tail structures would be primarily moldless foam core, with wing spar caps of pultruded carbon fiber. The wing would probably have fabric covered ribs aft of the spar. The ribs would be pan-molded parts made in simple particle board molds. The overall effect would be parts that are plenty strong enough for flight loads, but that marginal for handling loads so you'd have to treat them carefully. But that's no different from a Minimax. The canopy could be either a blown acrylic or PETG bubble, or a three-section Galland hood pieced together out of flat stock. Or just a windshield for open-cockpit flying. As I see it, the big downside against the Minimax is that wood is fun to work with in a way that carbon fiber isn't. Wood smells nice, sands easy, and is relatively hypoallergenic. So if what you want to do is spend pleasant hours fiddling in the garage, the Minimax is what you want. By contrast, you need gloves to work with epoxy, carbon sands to an itchy black dust, and the whole affair smells like Dick Cheney's wet dream. But you make progress fast, and in the end you have an airframe that is much more impervious to age and the elements than a wood one, and for which you don't need external bracing wires or struts. Of course, just like the Minimax, this airplane would have no great utility. It would be light and slow, and any wind or turbulence would really beat you up. It would be an airplane for early morning and calm weather flying. But it would assemble faster than the Minimax, with wings that go on with a pair of pins and ailerons that automatically connect. The wings would be light enough for a single person to attach at the airport.