Kreider-Reisner KR-34 Challenger (oz329)

About this Plan

Kreider-Reisner KR-31,34 Challenger. 30in RC Scale .049, pulse rudder by Jim Dean. Scale is 1/12.

Quote: "The OX-5 Challenger, by Jim Dean. A charming one-inch scale model of a Kreider-Reisner biplane of the 1920s. Equipped with a single-channel pulse proportional, it flies realistically on .049s - perhaps of a slightly tired variety. Worth trying!

Although not so well known as some of the other biplanes of the period, the Kreider-Reisner Challenger was one of the prettiest ships produced in an era when attractive airplanes were the rule and wings, rather than sheer horsepower, were used for flight. The design was about standard fror the time, being three-place, open cockpit, and with the Curtiss OX-5 engine.

The R/C Challenger given here is done 1 in to 1 ft. Information on the KR-13 was taken from NC-767-W and on the KR-34 from two other ships whose registration was, unfortunately, not copied at the time. However, at last report, one of the '34's - a Comet-powered version - was based at Baltimore. The other, a J-6 powered ship, is presently based at Somerset, Pa. The KR-31 is no longer in existence.

The model is small, light - about 16 oz - and the flight is extremely realistic. It is fun to fly even though it will not do the AMA pattern and is designed for pulse proportional rudder only. Anything else and you are on your own although it is possible that other systems may work well. (Wonder how it would do on multi in 2" scale?)

It isn't hard to build although the construction may seem strange and left field-ish to most R/C'ers. However, don't beef it up. It's plenty hefty as is and flight performance will suffer. All balsa used should be no heavier than medium weight - some of it a bit lighter - except for the wing leading edges. These may be hard balsa.

Drawing notes are almost complete but some additional info may be helpful, so here it is: Fuselage: Build the side frames one on top of the other. Before removing frames from board, cover top frame with 1/32in sheet. Grain of sheet must be 90 degrees to centerline of fuselage. When done, remove frames from board, do not separate, trim sheeting and cover..."

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