The construction of flying models is very different from most static models. Flying models borrow construction techniques from vintage full-sized aircraft (although models rarely use metal structures.) These might consist of forming the frame of the model using thin strips of light wood such as balsa, then covering it with fabric and subsequently doping the fabric to form a light and sturdy frame which is also airtight. For very light models, very thin paper can be substituted for fabric. Or, heat-curing plastic films ("heat shrink covering" or "solarfilm") can be ironed on - a hand-held iron causes the film to shrink and adhere to the frame. A hair dryer can also be used.
Home-grown model-construction techniques consist of using formers and longerons for the fuselage, and spars and ribs for the wings and tail surfaces. More robust designs often use solid sheets of wood to form these instead, or might employ a composite wing consisting of an expanded polystyrene core laminated with a surface veneer of wood, often obechi, which protects the core and provides strength. Such designs tend to be heavier than an equivalent sized model built using the traditional method, and would be much more likely to be found in a power model than a glider.
The lightest models are suitable for indoor flight, in a windless environment. Some of these are made by bringing frames of balsa wood and carbon fiber up through water to pick up thin plastic films, similar to rainbow colored oil films. The advent of "foamies," or craft injection-molded from lightweight foam and sometimes reinforced with carbon fiber, have made indoor flight more readily accessible to hobbyists. Many come ready-to-fly, requiring little more than attachment of the wing and landing gear. See: ParkZone Slo-V.
Flying models can be built from scratch using published plans, or assembled from kits. Plans are intended for the more experienced modeller, since all parts must be sourced separately. The kit contains most of the raw material for an unassembled plane, a set of (sometimes elaborate) assembly instructions, and a few spare parts to allow for builder error. Assembling a model from plans or a kit can be very labour-intensive. In order to complete the construction of a model, the builder typically spends many hours assembling the frame, covering it, and polishing/refining the control surfaces for correct alignment. Furthermore, the kit does not include necessary tools, and these have to purchased separately. Finally, a single overlooked error during assembly could compromise the model's airworthiness, leading to disaster.
To address these concerns, and increase the hobby's accessibility to the inexperienced and less interested alike, vendors of model aircraft introduced Almost Ready to Fly (ARF) designs. Compared to a traditional kit design, an ARF design reduces the amount of time, skill, and tooling required to assemble the model. The average ARF aircraft can be built with less than 4 hours of labor, versus 10-20+ for a traditional kit aircraft. More recently, Ready To Fly (RTF) radio control aircraft have all but eliminated assembly time (at the expense of the model's configuration options.) Among traditional hobbyist builders, RTF models are a point of controversy, as many consider model assembly as integral to the hobby. Brands associated with these types of aircraft include Great Planes, Hobbico, Carl Goldberg Products, Lanier RC, E-Flite , Hangar 9, GWS, HobbyZone and ParkZone.
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