Radio Control: Scale
REPORT FROM PARIS: There is definite reaction to the consequences of the complexity bonus system, now that it has done what was originally intended. In the past, simple aircraft were desirable as model subjects because they could be detailed and finished with minimum effort. There was also reasonable assurance that the model would fly well, in a scalelike manner. The bonus system was instituted to give models of complex aircraft a supposedly equal chance to become contest winners. Recent experience indicates that the complex, multi-engine and multi-function airplanes now have more than an equal chance, to the exclusion of simpler designs, and the balance between types has shifted too drastically. In other words, the modeler's choice of aircraft to be built is now influenced in favor of complexity and he is again obligated to build a model that suits the rules rather than the airplane he really prefers.
Radio Control: Scale
CONTROL CABLES: Control surface actuation by cable is commonly used on Scale models of aircraft that have exposed cables. Its most notable advantage is its light weight. In the short lengths we use in our models, there is no stretch and, therefore, no loss of motion, when using stainless steel cable intended for operation of Control Line models. The cable is inexpensive, found in most hobby shops, and is flexible and available in various diameters to suit model sizes. Its main disadvantage is that it cannot be soldered. Terminations must be made by swaging. Other materials have also been used, such as fish-line leaders and plastics, but our experience with these has been that even a slight amount of stretch is objectionable because motion is lost, and the loss varies with airspeed.
Radio Control: Scale
INSTALLING EQUIPMENT: Scale models with ornate cabin or cockpit interiors were once a rare sight. Today, modelers consider some amount of interior detail to be nothing unusual, although the really complete cockpit is not seen too often. The degree of completeness depends upon the modeler's desire to reproduce all aspects of the prototype and is somewhat dependent upon having access to a full-size aircraft to copy. Photos alone are a help, but there is no substitute for having direct measurements from an original. Adding seats, upholstery, and controls-for even the most spartan of interiors-can introduce a tight squeeze on space for servos, receiver, and batteries which always seem to occupy the space normally used by passengers in civil-type aircraft.
Radio Control: Scale
FLAP OPERATION: The value of flaps in model performance has often been argued. It's true, if a model has a low wing loading and never flies very fast, flaps are merely employed because they were used on the prototype, and the model's performance will change very little with flaps deployed. If the full-size airplane was fast and heavy, and the model also flies like a streamlined brick, flaps are indeed beneficial. Almost all modern planes (those built in the past 50 years) will have used some form of flaps. Their basic purpose is to allow decreased speed without loss of lift and to steepen the glide path for a more predictable touchdown in landing. Drag is increased considerably, and throttle may need to be added to compensate.
Radio Control: Scale
SCALE Speed Again: Bradford Powers ("About the Size of It," MA, Jan. '78) has some additional thoughts on that controversial subject, scale speed. He writes: "Since, from time to time, the subject of scale speed keeps popping up, it has occurred to me that in view of the growing interest in scale models, the formulation of rules for realistic speeds might be in order. "As I pointed out in my article, `About the Size of It,' most models approximate dynamic models and behave in more or less the same way, so that so-called `visual' speeds (1/4 the full size speed for a 1/4-scale model, for example) are unattainable short of something in the nature of a kite, or the Gossamer Condor. For example, the Sig Ryan at around 10 pounds behaves pretty much as a dynamic model and will have a landing speed of around 25 mph, since it is a 1/5-scale model. In order to reduce the speed at landing to 1/5 that of the real airplane, or 12 mph, the weight would have to be reduced to around two pounds, which I'm sure you will agree is unattainable for all practical purposes.
