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/142883
I t 's A ll A b o u t D e t a il s… in the early 1990s was anything but conducive to finding an airline job. So, as he puts it, he found a "real" job and gave up on the airlines. But that didn't stop his interest in aviation, and he discovered homebuilt aircraft almost immediately. "I've always been a high-horsepower, hair-on-fire type of guy," James said. "Even as a teenager, I was street racing in a 400-hp '70 Mustang I had built. I've always loved building stuff that goes fast. So, when I saw my first canard, a Long-EZ, then saw what kind of speeds the Berkut was promising on 180 hp, I was totally hooked. Plus its sexy, out-of-this-world appearance didn't hurt any." At the time the Berkut was introduced, it was viewed as the hot rod version of a Rutan Long-EZ. The design Painting Thirteen "I flew Thirteen for eight years in primer," said James Redmon. "Then when I was finally done hacking parts off the airframe, I wanted a paint scheme that would honor the original Berkut/EZ heritage and match Thirteen's racing history and sleek lines. It took nine months to develop the final scheme layout and dozens of conceptual designs, but I think it hit the mark. I think it actually turned out better on the plane than on paper! "This much black paint on a composite aircraft is unusual due to radiant heat absorption. To pull it off, I researched and found a solar heat reflective acrylic urethane paint that is used in Europe and by the military. It has infrared reflective additives in it that significantly reduce the solar heat absorption and transmission [of heat] to the surface of the composite structure. I tested samples in the Texas heat against other standard black paints, and it really does knock 40°F to 50°F off the surface temps so it remains well below the Tg (glass transition) of the epoxy and foam beneath." Visit www.ANAC.com to learn more. A brochure describing the paint is available at www.ANAC.com/brochures/akzonobel_solar_heat_ reflective_coatings.pdf. took up where Rutan left off and made everything bigger, more powerful, and slicker. An aerial hot-rodder himself, Berkut designer Dave Ronneberg had no interest in using the smaller engines originally used in the EZ series and designed a new airframe specifically for the 180-hp IO-360 series of Lycomings. Eventually, speed freaks stepped that up to monster IO-540s, and a couple even have turbines. The general attitude has been that "If big is good, bigger is better." "I really wanted to go fast," James said, "and I knew some guys were using six-cylinder engines, but that was just too far outside of my financial envelope. So I stuck with a 180-hp IO-360 and decided to substitute aerodynamic cleanliness for horsepower." The goal of the design was, above all, to get the most speed possible out of the horsepower available. So, drag of any kind had to go. The most obvious change Ronneberg made was designing the main landing gear so that the legs could be sucked up into the wings. According to James, "The gear legs are solid carbonfiber layups with metal 'talons' (axle reinforcements), are quite stiff and robust, and mount Grove dual caliper brakes. The retraction system uses hydraulics for the main gear and outer doors, while the nose gear has an electric linear actuator and mechanical doors. In keeping with the rest of the bulletproof airframe, the gear and doors are tough enough to be extended at any speed. It's estimated that retracting the gear was easily good for an increase of 15 mph at cruise power settings in this speed range." James put his deposit down on April Fool's Day in 1993, and the materials kit was delivered on Friday, May To learn more about James Redmon's Thirteen, including numerous other notable performance mods, visit www.Berkut13.com. Specifically, this webpage, www.Berkut13.com/berkut61.htm#cram, shows how James totally transformed his economy cruise and race power. 14 Vol.2 No.7 / July 2013 Photography by Jim Koepnick