Twin Cut: Not your ordinary twin-engined layout
TWIN CUT was begun because I like twin-engined aircraft and I like gasoline engines. I also wanted to try the new Cheetah 42 engine with its interesting C.H. Electronics Jump Start feature; easy starting engines would be an advantage in a twin. My first design thoughts were not promising; I only wanted to do a twin if it would be a good aerobatic performer, not complex, and easy to build, but also not so large that it would be a storage and transportation problem. My one previous twin gas-engined project was a Nick Ziroli DC-3; it was impressive and flew great, but I didn't want another 43-pound aircraft that barely fit in my minivan.
T-28
Military aircraft are always popular modeling subjects, and the North American T-28 has been well-liked by modelers since it first flew in 1949. I felt the T-28 would be an ideal choice for a Control Line profile project; the T-28's clean lines would be easy to fashion in sheet-balsa construction. The 1/2A-powered sheet-balsa profiles are a bargain way to enjoy CL flying; they're low-cost, easy to build, and offer plenty of aerobatic capability. Easy to underestimate, today's all-balsa 1/2As are not just a lump on the end of a string. With a good engine, sized correctly, and flown on 35-foot wire lines (rather than string), these airplanes can be put through most of the aerobatic pattern; not contest-quality maneuvers, but well enough for plenty of flying fun.
Electric One
For a fun model, we had designed the .19 powered Whiplash (published in Nov '74 AAM) and looked at this as a basis for an electric model. The overall size was increased somewhat to get a reasonably light wing loading. The airfoil was changed to semi-symmetrical; this would give us a better lift capability but still be aerobatic. A full 4-channel installation was planned. Basic aerobatic design-tapered wing, strip ailerons, generous rudder area, etc.-were all used to insure good performance. Nothing revolutionary, just sound basic proportions. Fuselage size was kept to a minimum. This presented the biggest problem due to the size and weight of the necessary battery packs for the Astro-25 motor. The unusual arrangement of the servo installation behind the wing, accessible through a hatch, enabled us to achieve a normal balance point for the aircraft. The wing was built-up rather than foamcored, for lightest possible weight. Using vertical spar webs gave the necessary strength. Plywood fuselage doublers are believed necessary because of the battery weight.
Computer Program: For Analysis and Comparison Of Aircraft Designs
RESPONSE to our computer program (for canard aircraft design assistance) presented in the June 1984 issue of Model Aviation has been positive and enthusiastic. Apparently our assumption that many modelers have home computers and want to use them for modeling purposes is correct. Our program was put to good use assisting in the design of a new canard Pattern aircraft, which was published in Flying Models magazine. Since then we have developed another computer program which we feel can be even more helpful to modelers. Why does one airplane perform better than another? What changes in the design make it better? Which airplane should you build next?
Firebolt
WHY BUILD a forward-swept wing (FSW), twin-finned, jet-styled pusher canard? Because it's modern, striking in appearance, different, fun, and best of all, it flies well. It's not Scale, and it's not optimized for Pattern flying, but it handles like a good Pattern/sport model. With a full-symmetrical airfoil, it's aerobatically capable; inverted passes, inside and outside loops, rolls, etc., are all easily handled.
