Pied Piper (oz3921)

About this Plan

Pied Piper. A 30 inch span C/L Rat Racer. From MAN, May 1959.

Quote: "After a direct hit in his Woody (oz9183) combat, your old Wyoming fire breather has another hot airplane, this time a proved rat racer.

The Pied Piper, by Bill Judge.

Design. Rat Racing is divided into three important parts: the model, the motor and the crew. We intend discussing only the first two, but in closely competed races the pit crew is just as important as the model and the motor.

In designing a model for any event, one should consider the problems peculiar to that event. The best model is the one that answers those problems most satisfactorily.

In Rat Racing we need a model capable of maintaining a high average top speed. Every portion of the design must contribute to this speed. So we must consider fast and easy service by the pit crew, ground stability, fast acceleration, flight stability and top speed.

The Pied Piper is strong in all these departments. It weighs in at 15 ounces, without fuel. This means fast acceleration, short take-off space and lower impact on landings.

The parts that do the most work and absorb the most punishment, the motor and tank mount, the landing gear and bell-crank platform, are beefed up in an integrated unit. The typical weakness of the profile model, the joining of the wing and fuselage, is not present in the Pied Piper. This joint is more solid than in most box-fuselage models.

Since the motor is profile mounted toward the outboard wing and the bell-crank is inboard mounted, perfect control is maintained at all times without extra weight in the outboard wing tip.

The center of gravity is well back, and the wheels are well forward and wide apart for good ground stability. A team racer type landing gear avoids bouncy take-offs and landings. The center of lift is located at 35-40% of chords, the aspect ratio is seven to one. The center of gravity and center of resistance are located below the thrust line. All of these points contributing pod flight Stability at all speeds. There is no hunting or tail wagging in flight.

The fuel tank is pressurized by slip stream and well located for easy starting and good fuel feed at high speeds. The tank is of sufficient size to accommodate .29's or .35's and for experimenting with different fuels and props.

Motor and tank are out in the open, run cool, and permit easy service by the crew, Quite often green crew men have to be used; consequently, the less complicated the starting procedure the better. Under the rules you can use a fuel shut-off or not, as you prefer. With the use of green crew members, the wisest choice would be just a tank.

The wing features a new type of con-struction easy for those of limited experi-ence. It is light but sufficiently strong, since the center of the model absorbs the punish-ment. The wing is a thin, lifting, speed type which tapers toward the tips. The stab and elevator areas are large, and shaped to give good control at all speeds with low proportionate braking action. This model can be looped or figure-cighted.

Construction. Start from the bottom up when building the wing. Place waxed paper over the plans. The planking for the leading and trailing edges go down first, then the cap strips and the center plywood platform after it has been drilled for bellcrank and landing gear. Blind mounting nuts are used for the landing gear and Phillips-head bolts are the right length to allow clearance for the bellcrank. After fitting, the landing gear is added when the rest of the model is completed.

Before adding ribs, place bellcrank in position and draw lines where the lead out wires go. Wires go between the ribs and the bottom cap strips, so ribs are temporarily located, wire positions marked, and ribs notched before cementing..."

Supplementary file notes

Planfile includes article.

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