Originally published May 1992
Before I get started on my latest and greatest idea this month, I'd like to make some comments about the concept of the design group. Our chapter has quite a few engineers, high time military pilots, test pilots and now even a future astronaut. I'm quite proud to be a part of all of this and tend to brag about it to potential future members of our chapter when I'm trying to convince them to join us. The reason I bring this up is that I have sometimes gotten the reaction of "I'm nothing special" from these people, implying that if you aren't in one of the above mentioned categories, you wouldn't fit in. This is absolutely not true of our chapter or the design group either. The only requirement to join the chapter is membership in EAA and a love of airplanes. The only requirement to come out and join us at Burger King after the chapter meetings is to love to talk about airplanes. It's the exchange of ideas and the enjoyment of being in a group who share the same interest that is the important part of what we do.
This month's topic came out of a discussion between Bob Waldmiller and I as we drove home from the chapter 49 meeting earlier this month. We were talking about what type of transportation you would need if you wanted to travel around the country but not be tied to any one place with things like vehicle registrations and drivers' licenses. The things that I thought of were ultralights and mopeds. The next logical step was to combine the two. I know some of you don't think much of either of these vehicles, but it is a fun concept to play with and it led to some interesting ideas.
The basic vehicle would be a three wheeled recumbent bicycle. This would provide the ground machine and be the fuselage of the aircraft. A small moped type motor would be used on the ground and the whole thing would be designed to fit into the moped rules so you wouldn't need a license or registration for it. The moped, instead of pure bicycle approach, would make it more practical as ground transportation. It would be important to keep the whole thing as light as possible, maybe as little as 100 pounds, including the weight of all the flying parts. "How do I accomplish that?", I hear you ask. There are several things that could help. The first is to use a very light engine. At Oshkosh last year Limbach had a two cylinder, two stroke engine that was designed for military use in drones and remotely piloted vehicles. It produced 20 to 25 horsepower from 275 CCs and weighed in at 16.5 pounds. The second is to use very light composites, like carbon, for all of the structures. The third is to steal an idea that is used in some kites and parachutes. Instead of using solid ribs in the wings you use all fabric with the wing shape sewn up in cells. The leading edge of the cells is an open mesh fabric and the force of the air blowing on the leading edge inflates the cells and gives the wing its shape. Add a leading and trailing edge spar plus a strut brace and you could have a complete wing that weighs in at maybe 15 pounds. Make the spars so they break down into shorter segments and nest inside each other for storage and you could carry all of the airplane parts with you in compartments built into the bike. Once you do that, you have the ultimate low end personal transportation. You could drive out to an open field, assemble the airplane, fly wherever you wanted to go and have ground transportation available when you got there. Of course the concept could be expanded to a larger vehicle that would carry more that one person and have to be licensed as a motorcycle and experimental aircraft. I also think the ram air inflated fabric idea has some interesting possibilities for use in experimental aircraft.
Molt Taylor did the aerocar long before I was old enough to drive or fly, so the general concept isn't new, but I don't think I've seen the moped/ultralight combination before. The important thing, though, is the enjoyment of coming up with an idea and working out the details. This idea probably wouldn't have come to me if Bob and I hadn't been having the conversation that we did.
Getting back to where I started from this month, that is what I really want from the design group. The chance to exchange ideas, to come up with new ones by going down paths that you might not have thought of on your own, to have someone come up with the crucial concept or direction that makes something work. Bring your imagination and I'll see you at Burger King.
Contents of The Leading Edge and these web pages are the viewpoints of the authors. No claim is made and no liability is assumed, expressed or implied as to the technical accuracy or safety of the material presented. The viewpoints expressed are not necessarily those of Chapter 1000 or the Experimental Aircraft Association.
Revised -- 27 April 1997