Alfa Model Ltd.
The production programme of the Alfa Model company is the design and manufacture of flying scale model kits of real aircraft. Our models are quite simple to assemble and stand apart by their excellent flying qualities and performance. An already well-flying model could be enhanced by adding further details as the builder may like and can, increasing the scale-like appearance while keeping its excellent aerodynamic performance.
The Alfa Model kits are manufactured using the extruded polystyrene foam, shaped by vacuforming. They are of a monocoque design, in the highly-stressed places reinforced as necessary by plywood or balsa stiffeners, doublers etc. The base plastic material has an integral surface layer, or skin, that markedly increases the resistance of the generally soft polystyrene foam to scratching, denting and gouging. Parts of the model that suffer most, e.g. during landing, are further protected by plastic covers (sheathing), which are virtually immune to a damage from routine operation.
A model designed according to the previous principles possesses the following advantages:
- For the given physical size it has the minimum possible weight of the airframe, while maintaining its necessary strength and stiffness.
- A model could be produced having a smooth surface, that nevertheless allows for a very realistic rendering of the scale features in detail. The fine, exact contours and the possibilities our production methods offer (e.g. the proportionate thickness of the sections of wings and other aerodynamic surfaces, especially of their trailing edges) ensure low total drag of the model, which, combined with the choice of suitable wing and empennage sections, provides for the high aerodynamic finesse.
- The proper aerodynamic design ensures that the model has excellent flight characteristics in the available band of velocities. It shouldn’t be forgotten, however, that the neutral (trimmed) position of the elevator (as applies mainly to the models with excess of power) has to be adjusted according to the momentary speed of the model – the same as it is with the full-size aeroplanes, where the position of the horizontal stabilizer/trim tabs has to be trimmed – i.e. adjusted according to the flight regime/speed.
- Compared to other companies’ models, produced using the technology of polystyrene expanded in moulds (usually suffering from higher weight and porous surface), our models have the same performance, but with a less powerful propulsion unit. Or, vice versa, in case of the identical propulsion unit, our models have a higher performance. These differences are most noticeable when the models are flying at higher speeds – i.e. it applies especially to the models of jet aircraft, propelled by ducted fans. The total drag of the model is proportional to the square root of the velocity, while the increase of the required power (battery drain) due to the porous surface is very high. This applies to the internal air duct too – the smooth and well-designed one ensures higher efficiency of the propulsion (ducted fan) – the airstream velocity in the duct is markedly higher than the velocity of the model itself.
The (semi)monocoque models of extruded polystyrene have also some disadvantages:
- Their manufacture to precise shape requires a larger number of tools and jigs/moulds, while the actual production time is substantially longer than with the models made of expanded polystyrene. This tells on the somewhat higher price of our monocoque models.
- It is a matter of chance what damage would a model suffer during a crash and how demanding would be its repair. It applies universally, however, that the repair of monocoque models is generally more demanding that of the solid-foam (expanded polystyrene) ones.
If you are a modelling beginner or just an occasional model flyer, the models made by the expanded polystyrene technology may suit you better for their price and simpler repairs. These models are often available as ARF – with decals applied, an installed powerplant and sometimes with the RC set in place.
The kits by Alfa Model, however, are intended for the more advanced modellers, who appreciate more their appearance and performance. These modellers would most often choose the powerplant according to their own preferences and the same applies to the RC set. The Alfa Models are finished in the base colour scheme according to the prototype airplane, but, thanks to the decal set supplied with the model, they allow for a choice of several paint and marking schemes authentic for the given type of aircraft.