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.
Issue link: http://experimenter.epubxp.com/i/234576
Jim Clement with his latest (last?) Tailwind, N168WH. the ride. Precision isn't called for until you begin to mount the tail surfaces. "This is an airplane that you establish the critical points exactly, like the wing and tail attachments, and build the airplane around those. You can't trust all of the dimensions in the plans enough to build complete components and expect them to bolt together. If it's a critical fit, you do it on assembly, not on the workbench." As part of Wittman's keep-it-simple approach, many components, such as the rudder pedals, are welded in place. Once installed, they're in to stay. That's one of several things Jim changed. "The rudders and brake pedals mount to a cross piece that's usually welded in place," said Jim. "I bolt that cross member in, which makes sandblasting, painting, and lubing the pedal assemblies much easier and cleaner." Jim also modified the shape of the doors, which were originally difficult to climb through because the rear edge was too far forward. With Wittman's input, he moved the rear wing spar carry-through back 3 inches and triangulated it. This opened up the cabin roof while at the same time allowing the edge of the door to move back. This is another of the plans addendums that he sells to builders. "The wings are incredibly easy to build," Jim said. "Very, very simple, and if you use Okoume ply rather than aircraft mahogany, like a lot of the aerobatic guys do, and Douglas fir spars, they are cheap to build. I get my spar material from a lumber yard that carries cabinet-grade materials. At places like that, you have a lot of wood to sort through, and it's not hard to find straight grain pieces with very little to no grain run-out." When it comes to painting an airplane, Jim is old school for good reasons. "I've done a couple in urethane, but I really prefer Randolph butyrate dope," he said. "It's easy to do, nonlethal, easy to repair, and cheaper. Besides, I just like it better." Is Another Tailwind in the Wind? Jim has been finishing a house and flying his current Tailwind, but his new workshop is empty. While talking to him about it, he said he's not likely to build again; airplanes have become too expensive. But he does have several sets of finished wings racked up in the new shop. And there's all of that extra leftover tubing. And the tools are just sitting there. Anyone want to make bets that his shop won't be empty long? Budd Davisson is an aeronautical engineer, has flown more than 300 different aircraft types, and published four books and more than 4,000 articles. He is editorin-chief of Flight Journal magazine and a flight instructor primarily in Pitts/tailwheel aircraft. Visit him at www.Airbum.com. EAA Experimenter 15