Construction
The construction of flying models differs from that of most static models as both weight and strength (and the resultant strength-to-weight ratio) are major considerations.
Flying models borrow construction techniques from full-sized aircraft although the use of metal is limited. These might consist of forming a frame using thin planks of a light wood such as BALSA to duplicate the formers, longerons, spars, and ribs of a vintage full-size aircraft, or, on larger (usually powered) models where weight is less of a factor, sheets of wood, expanded polystyrene, and wood veneers may be employed. Regardless of the underlying structure, it is then skinned and subsequently doped to provide a smooth sealed surface. For light models, tissue paper is used. After it is applied, the paper is sprayed with a mist of water, which causes the paper to shrink when it dries. For larger models (usually powered and radio controlled) heat-curing or heat shrink covering plastic films or heat-shrinkable synthetic fabrics are applied to the model then heated using a hand held hair dryer, laundry iron or heat gun to tighten the material and adhere to the frame. Microfilm covering is used for the very lightest models and is made by bringing a wire loop up through water to pick up a thin plastic film on the surface made from a few drops of lacquer spread out over several square feet.
For a more mass market approach, “foamies,” or aircraft injection-molded from lightweight foam (sometimes reinforced) have made indoor flight more accessible to hobbyists. Many require little more than attachment of the wing and landing gear.
Flying models can be assembled from kits, built from plans or made completely from scratch. A kit contains the necessary raw material, typically die- or laser-cut wood parts, some molded parts, plans, assembly instructions and has usually been tested. Plans are intended for the more experienced modeller, since the builder must make or find all the parts themselves. Scratch builders may draw their own plans, and source all the materials themselves. Any method may be labour-intensive, depending on the model in question.
To increase the hobby’s accessibility to the inexperienced, vendors of model aircraft have introduced Almost Ready to Fly (ARF) designs which reduce the time and skills required. A typical ARF aircraft can be built in under 4 hours, versus 10–20 or more for a traditional kit. Ready To Fly (RTF) radio control aircraft are also available, however among traditionalists, RTF models are controversial as many consider model building integral to the hobby.
