Kyosho super stearman 40

Model Airplane News, Nov 1999 by Chianelli, Chris

THE FACT THAT ARFs will remain a permanent part of our hobby in the foreseeable future is, I think most would agree, a foregone conclusion. Like it or not-and I happen to like it-ARFs are here to stay. When I entered this hobby in the early '70s, ARF technology was at a stage in its development that was characterized by fuselages of vacuum-formed, ABS plastic skins over wooden crutches and wings of molded foam covered with soft vinyl. With these early ARFs, the "R" part of the acronym was, at best, dubious; "a bit of a stretch," so to speak. It wasn't that the building procedure had a lot more steps than today's ARFs, but those of us who were used to working with balsa and plywood found that the techniques needed to work with hard, plastic, vacuum-formed components were perplexing.

The next big milestone in ARF technology came in the mid-'80s. This period of development has been referred to as the "EZ-era." The EZ technology was pioneered by a Japanese company called Sports Aviation. EZ kits featured a thin, triple-layer, plastic/Mylar skin stretched over formers and ribs. These kits looked great, were light, flew very well (for the most part) and were far easier to assemble than previous ARFs. EZs were quite popular and were copied by other companies. But anything more than minor crash damage was very difficult-if not impossible-to repair.

Somewhere along this "ARF" timeline, all-wood types were being developed and were growing steadily more popular all the while. I always liked all-wood ARFs because they were built from a material with which I was very familiar. Liking them as I did, I knew I could end up with a better built, lighter weight model if I built it myself; that is, until I opened the box containing Kyosho's* Super Quality Series Super Stearman. After closely inspecting the fuselage, wing panels and tail group, I had to ask: could I have built this thing any better myself? My answer is an unabashed "I don't think so." And I do consider myself a good builder. I'd better at least be "good," after all these years.

THE KIT

The Super Stearman is superbly crafted and, in my opinion, represents the end result of many years of all-wood ARF "evolution." And this SO-inch-wingspan biplane does have the bottom-line numbers to back up my bold contention; that is, a light wing loading of 18.47 ounces per square foot. That, you can't fake! Moreover, this lightness is accomplished while keeping the airframe rigid. The Super Stearman is far from flimsy and will stand up to rough landings as well as any other conventionally built, all-balsa-andplywood model.

As you can see from some of the detail shots on these pages, Kyosho has gone to the limit with this model. From its fully stringered fuselage to its built-up tail group, the contents of the box oozed precision and quality. The balsa throughout is superb, and all structures are covered and detailed with an iron-on film that seems to be quite sag-resistant. Some examples of Kyosho's attention to detail include a fiberglass cowl (prepainted, of course), and a tempered-aluminum landing gear. The only thing I can find to criticize (I had to find something so you'd believe the great things I'm saying about this model) is the choice of screws and nuts for use in securing the cabane and interplane struts to the wings and fuse; they are 3mm Phillips-head screws and plain nuts. Now, I don't care how well you balance your prop; plain screws and nuts holding metal struts to metal stay brackets are going to vibrate loose. End of story. I recommend you replace these screws and nuts with Allen capscrews and locking aircraft nuts. They will not only stay put, but it's also a lot easier to install 12 sets of tiny screws and nuts with an Allen ball driver than with a Phillips-head screwdriver. Believe me; I've been there, and I have a screwdriver hole in the bottom wing covering to prove it! Other than these particular screws and nuts, the rest of the hardware that comes with the kit is of very good quality, and I used it all (tank, wheels, pushrods, devises, steerable tailwheel, etc.) when I assembled the Stearman. If I don't like kit-included hardware, I'll replace it in a real hurry with something I know and trust.

ASSEMBLY

The best way I can characterize the assembly of the Stearman is that it fits together like a precision puzzle. In this case, though, Kyosho gives you a 16-page instruction manual with more than 100 pictures and diagrams to tell you exactly where each part of the puzzle goes. There's no guesswork involved. The best illustration of the nearly perfect fit found throughout the building process is demonstrated in the cabane and interplane strut fit. To start, the holes for the 12 strut-anchoring "L" brackets are predrilled and placed perfectly on the wings and fuselage. The various obtuse and acute angles needed in the "L" brackets and cabane struts are prebent exactly. To make a long story short, when it was time to bolt the wings to the fuse, all the holes in both the cabane and interplane struts lined up perfectly with the holes in their corresponding "L" brackets. Not even the slightest bending or other "coercion" of any kind was needed to get everything to line up and bolt together. This level of precision fit makes building such a pleasure. I think the only time I used expletives during the entire building process was when I dropped tiny screws onto my messy shop floor or watched spilled CA glue eat its way though the Robart foam fuselage cradle I use during construction. Assembling this model was pure joy for me.