Dart III (oz6518)

About this Plan

Dart III. Radio control sport model.

Quote: "Dart III, by Captain Charles T Winter, USAF.

WHY the Dart III? It's like asking - Why do we need a good five-cent cigar? The Dart III concept was originated out of the frustrations of a model builder who believed that the majority of radio control model airplanes being built and flown today are lacking both in creative design and construction.

I have been building and designing model airplanes for over 20 years. During the mid-forties, when I was an avid U-Control enthusiast, I was directly involved with the development of the aluminum speed pan. A design called the Hell-Razor (oz462) which terrorized the contest circuit for many years and reached the then unheard of speed of 159 mph on two .016 wires for the world speed record, was designed by George Fong, Fletcher Slade, and myself. My credentials include a college degree in Mechanical Engineering, plus a year of Aeronautical Engineering. After finishing school, I worked for Republic Aviation, Long Island, NY. The project to which I was assigned at Republic was development of the hydraulic and control systems of the F-84F jet fighter.

After one year with Republic the jet engine roar got to me, so I tried my hand at making some noise myself by joining the US. Air Force. I have since logged over 3,000 hours in 13 years of flying jets. I feel I should mention at this point that I hold the unofficial world model airplane speed record; a window-rattling 860 mph. I accomplished this momentous feat by taking one of my Hell-Razor speed planes with me during a supersonic mission in an F-86D all-weather interceptor! I guess I hold the altitude record for model airplanes too - 45,000 feet. At present, I'm flying F-106 all-weather interceptors and could easily increase my speed and altitude record, were they ever challenged!

Let's get back to the reason for this article - Why the Dart III?" During the preliminary design layouts, I wanted an airplane into which any radio control equipment could fit, plus additional room for those thick, clumsy fingers that can never reach that elusive little do-dad that needs adjusting or tightening. The radio and servo compartment measure a spacious 3-1/2 inches wide, 13-1/2 inches long, and plenty deep. It is also designed to allow the servo tray to extend into the fuel tank compartment. This permits mounting the battery pack on the servo board. You can now change the entire radio-servo package from one plane to another without that unpleasant job of digging the battery pack out from under the fuel tank.

The question most frequently asked by fellow model-builders is why I have designed the wing and horizontal stabilizer with swept tips. My first reply to this question is, Why not? The aerodynamic reason is that I have combined the desirable characteristics of both the swept and straight wing. The low speed handling of the Dart III is nothing short of outstanding. The swept tips aid in yaw stability by increasing the drag on the tip that may move further forward due to yaw or slip encountered accidentally or on purpose. At high speeds, the Dart III will fly a perfectly straight line, called 'grooving' by many model builders.

The over-all flight stability is enhanced by the effective vertical stabilizer area which starts from the rear of the canopy and develops from that point rearward. The length of the Dart fuselage is deceiving. It measures a surprising five feet from the nose to the furtherest aft point on the vertical stabilizer. A look at the horizontal stabilizer will reveal nothing earth-shattering. The feature worth mentioning is the location of the horizontal stabilizer with relation to its moment from the aircraft center of gravity. The tail moment has been designed to be short. This takes full advantage of the proportional type radio control equipment available today.

The fuselage construction is only slightly different than most. The engine was side-mounted to give a more aero-dynamically clean appearance. I deplore inverted engines with their starting prob-lems, and digging dirt out of the carburetor and cylinder head after an unscheduled bad landing. The side-mounted engine offers no problems. You can mount the engine on either side by simply flip-flopping the two engine mounting bulkheads when building the forward section of the fuselage.

A close look at the nose gear installation will reveal that it is mounted slightly off center to allow it to clear the motor mount. This offers no problem and is visually undetectable to anybody admiring your aircraft... "

Supplementary file notes

Article pages, text and pic, thanks to theshadow.

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