December 2013

Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other light aircraft.

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Page 13 of 40

A Ta l e o f 10 Ta il w in d s…a n d C o un t in g to anything in the engine compartment. So, it was essentially a new engine. I made him a bid before he put it on the Web, and I was off running on another 180-hp W-10. I have 100 hours on it now, and I'm certain that I'll never build a better airplane than this one. Plus it tops out around 220 mph, so I'm definitely not going to sell it." Wait! Haven't we heard that before somewhere? What hasn't been mentioned is that mixed in among all this building somewhere is a Hyperbipe project that Jim finished as well as a scratchbuilt clone of Wittman's lesser known design, the 1938 Buttercup that Wittman built as a proof-of-concept airplane for Fairchild to produce. Earl Luce puts out plans for that design (www.LuceAir.com). Also mixed in with all of this airplane building was his day job of running what was essentially a one-man body shop, along with raising three kids, either one of which is a fulltime job. He does, however, admit that much of the airplane work took place in the body shop, so we know what he did during his coffee breaks. Still, Jim makes the rest of us look like underachievers, doesn't he? Then, as if that doesn't make us mere mortals feel bad enough, of the 10 Tailwinds he has built, five have won Bronze Lindys at Oshkosh, and the second tri-gear was Grand Champion Plans Built at the Sun 'n Fun Fly-In in 1998. Jim, however, is quick to say that none of this would have happened had he married someone else. He said, "Donna and I have been married for 49 years, and she has put up with all this and also had full-time jobs after the kids were in school. If she wasn't such a good sport, I could not have done any of this and still be married." The Tailwind: Simplicity Breeds Success There are generally a lot of very basic reasons why one aircraft design is more successful than another. Today, in a world populated by quick, quicker, and quickest quickbuild kits, success is almost always a combination of a good flying airplane, kits that go together both easily and quickly, and enthusiastic customer support—for example, Van's Aircraft. Eliminate any one of the foregoing, and the product will have lackluster sales. Scratchbuilding shares some of the same requirements but definitely not all of them. Scratchbuilders, for the most part, are a much more independent breed, and problem solving is one of their real joys in life. They love working out ways of doing things. They don't need a customer service rep to tell them Tab A goes into Slot A. This is especially 14 Vol.2 No.12 / December 2013 true since a scratchbuilder has to hand-make both the tab and the slot. That having been said, however, the simpler, more straightforward the structure or component, the easier it is for a garage craftsmen to make the part with no outside help. That alone guarantees more of a given type aircraft will be finished. And the more that are finished, the more good things that will be said about it via word of mouth. This, of course, assumes the finished products are good flying airplanes and give the builders something they can't get elsewhere for anywhere near the same price. This is why so many single-place Pitts and Hatz aircraft have been built. And this is why so many Tailwinds are flitting around: They were designed to be built in a single-car garage with a hacksaw, a welding torch, and a hand jigsaw. So, when a guy has any more tooling than that and his experience includes hands-on building, the Tailwind goes together relatively quickly. Jim said, "I can build up the basic fuselage cage, including welding, in something less than 60 hours. Granted, this isn't my first time, but it's an incredibly simple structure, and Witt had an ingenious way of eliminating jigs almost entirely. "You tack up the sides in the typical, flat-board-withblocks fashion, but when you stand the sides up to add the cross pieces, you don't build a complex jig. First, you lay the sides on top one another. Then you run a short weld bead, a heavy tack, really, at the rear end that holds the two longerons together at the rudderpost station. Then you stand the sides up on a table that has a centerline on it. Spread the sides apart and insert the piece of tubing that is the rear spar carry-through, center it with a plumb bob, and lightly tack it. So, now you have a fuselage standing up, but the firewall station is far too wide. Then, and this is the secret, making no effort to heat-bend anything, you tack the front/main spar carrythrough in place. To do that, you have to pull the longerons in to meet the main spar carry-through. A ratchet strap or a piece of twisted wire with a stick through it will pull them in. When you do that, the longerons behind the rear carry-through that you have already installed take on a very symmetrical, pleasing curve all the way to the tail post. "Once the basic form is established, you spend some time making sure the front and rear spar carry-throughs are parallel and perfectly square. Generally, the tail post station will stay right on centerline. Then you just measure where the top and bottom cross pieces and diagonals in the aft fuselage should be, cut and fit them, and tack them into position. Super precision isn't necessary because everything in the aft fuselage is just along for Photography courtesy of Jim Clement

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