Control Line Aerobatics
AS I'VE MENTIONED BEFORE, I make so many mistakes that they make good copy for the column. This time I'd like to reflect on the past building season for lessons learned. Hopefully, you'll find something useful so that you can improve your own "program." Philosophically, it's a good idea to honestly evaluate the season just completed, list what went right or wrong, and then figure out what goals to set for next year. As it turns out, the number-three Caudron I flew this year was a very good airplane with a few faults: it was a bit large at 750 square inches, and there were time when it wanted to pop out of maneuvers in heavy air. I really wanted to find out why an otherwise excellent airplane should occasionally manifest erratic characteristics.
Control Line: Aerobatics
FOR THE LAST SIX MONTHS, George Aldrich and I have been working with Willie Wylie to develop a turned-pipe Stunt engine based on Willie's very successful Fast Combat engines. His engines are examples of the finest craftsmanship. The path to a really good Stunt engine was not a direct translation from a 20-25,000 rpm Combat engine. We started with the basic timing of the OPS SPA, and from the very first flight, the prototype showed some very nice characteristics. The airplane used for the tests was a well-tested, competitive model that I have used for all my initial pipe testing. It is a large model at 710 square inches, 63-inch span, and 61 ounces. All the associated equipment such as pipe, header, fuel, prop, etc, were well known, so the engine was only variable in the test program. The goal was to develop an engine at least equal to the sweet-running OPS .40.
Control Line: Aerobatics
THIS YEAR'S VINTAGE Stunt Championships (VSC) were attended by one of the series' originators, Mike Keville. Mike has missed the last few events due to his job in Saudi Arabia. This time he was spectating, beaming at how mature the whole format has become. This is in great part due to the hard work of his wife Jo Ann, who has been directing the contest for some years. As I've stated many times, the essence of the weekend really transcends pure competition. However, there is competition if you want it. The fun-fly aspect brings out many different aircraft, flown by the original designers. This helps recapture the feeling of years past, and preserves the history of the event.
Control Line: Aerobatics
READERS OF THIS COLUMN will recognize Ron Burn as a master builder of near-scale Stunters. His latest, a Macchi, is an extraordinary example of his Scale techniques-both in finish and fidelity. This month I'll highlight the molded-component technology Ron used in this fine model. The wing is a true monocoque structure-a one-piece molded surface of carbon/balsa/carbon. All carbon is 1/2-ounce mat; the balsa is 6- to 8-pound 1/20 sheet. Other composite combinations were tried, including carbon/Kevlar, glass/glass, and Kevlar/Kevlar. The carbon/carbon combination had the best combination of strength and stiffness. The Kevlar was very strong, but not very stiff. The skin-molding process is fairly straightforward. A solid wing core is cut from dense (3-pound) blue foam, then re-cut .080 undersize. It's covered with one piece of .010 Mylar using 3M Super Spray Trim Adhesive, and is vacuum-bagged for 12 hours.
Control Line: Aerobatics
SAFETY IS ALWAYS a consideration, but sometimes it's more paramount than others. When we don't think about it, we become vulnerable to a variety of accidents that can potentially be life-threatening. Consider the control lines we use. Nothing could be more benign-or could it? Look in your kitchen-cheese cutters, egg slicers, and mushroom slicers employ wires as the cutting tool. In the wrong set of circumstances, you can be injured by the flying lines. The chance of this may seem remote, but a CL accident happened to a very experienced individual just a few years ago:
