76 Special (oz9210)

About this Plan

76 Special. Radio control quarter midget trainer, for 3 to 4 channels.

Quote: "If you fly in an area where Quarter Midget racing is extremely popular, the urge to participate will certainly capture you in a short time. Many newcomers to our hobby try the old standby, the Goldberg Falcon (oz2424) for their first attempt. The average beginner will quickly progress to something like a Kaos (oz6251) and then, as soon as possible, try his luck at Quarter Midgets. In a real sense this jump can be quite startling to say the least. It was the intent of the '76 Special' to bridge this gap and provide the racing newcomer with a good feel for what the high performance racer is like.

To duplicate the average Quarter Midget pylon racer certain basic parameters were chosen, for example, a 300 sq in wing, 2-1/2 pound design weight and of course a .15 size engine. Airfoil thickness was increased to an NACA 2412 section (12% thick) for additional lift (and drag to slow the plane down a little). To simplify construction, a mid-wing configuration was chosen with the wing itself permanently attached to the fuselage. This eliminates the wing hold-down bolts which trouble so many R/C builders. The wingspan was set at 36in so that standard balsa wood sizes could be used, without excessive waste. With a 36in span, the model can be easily transported, fully assembled. A removable top hatch cover exposes all the radio equipment and the fuel tank for easy maintenance.

The Super Tiger .15 R/C engine and muffler are simply hung on the nose without any cowling. This simplifies the building and engine installation. The nose length was intentionally made quite long so that the beginner would have no problem in achieving a good forward C.G. position. Also the long nose moment tends to dampen the pitch (elevator) control which can be a great help to the new racing pilot. Finally I chose a T tail, strictly for appearance. To strengthen this tail I placed a balsa dummy canopy directly in front of the vertical fin.

The end product is a simple to build, easy to fly R/C model; which is very inexpensive to operate. Speed wise it won't compete with a Rossi .15 powered, Quarter Midget, but it is still very fast and yet quite controllable. Takeoffs and landings while reasonably gentle, do approach the feel of a full fledged Quarter Midget. If you can master this design then your next step is the real thing..."

The 76 Special, Flying Models, May 1976.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

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