Scale Classes

The SAMAA Scale Rules consist of a logical system of three classes based on the International FAI Scale Rules, which are structured in such a manner that the novice scale modeller may progress from one level to the next by developing his building and finishing skills whilst perfecting his flying skills during this progression. The flying section of all three classes is exactly the same as the FAI Rules in order to make transition from one class to the next seamless on the flying side.

Sport Scale

This class was introduced as an entry level scale competition and has proved to be a quite popular class. It is a flying only class with the only requirement regarding the model being that it must be a recognisable model of a full size man carrying fixed wing aircraft. If the model is painted in a documented colour scheme the pilot receives a bonus score which is added to his flight score. Sport Scale is a locally developed class offered up to Nationals level only.

International Stand Off Scale - F4H

This class comprises of a Static and Flying section. The model is statically judged against documentation supplied by the contestant regarding outlines, colour and markings and realism from a distance from the model. The static criteria are significantly less stringent than in F4C and no close-up scrutiny of the model is allowed. The flying section is exactly the same as for the other two classes. In F4H the weight of the static to flight scores is 1:2. F4H is a World Championships class with a World Championships which is held every second year.

International Scale - F4C

This class can be considered to be the most demanding scale class since the model needs to be as accurate as is humanly possible in all aspects in order to gain top Static points. This class is often termed “Museum Scale”. Static judging includes close up scrutiny of the small scale details of the model. The flying section is the same as for the other two classes. In F4C the weight of static to flight scores is 1:1. F4C is a World Championships class with a World Championships which is held every second year at the same time and venue as F4H.

About NASA

To many aeromodelling enthusiasts the building and flying of accurate miniature copies of full-size aircraft under full control, ranks as the ultimate achievement in aeromodelling. The scope of scale modelling is limitless, ranging from re-creating, in miniature, any aircraft from the original Wright Flyer to the most modern and sophisticated jet-powered aircraft; from simple home built aircraft to multi-engined behemoths; from tiny electric powered indoor models to giant 1/3 to ½ scale replicas.

Many scale orientated aeromodellers are content to just build and fly their models without concern for the pressures and excitement of competition, just for relaxation and fun. These semi-scale models often lack the fine detail that prevents their owners from entering them in competitive events. However, just like in many other endeavours, competition is the greatest spur to development, and it is an important facet in the growth of this exciting branch of aeromodelling.


NASA is the Special Interest Group of the South African Model Aircraft Association that is involved with the development of the competitive aspects of scale aeromodelling. Locally, NASA has created the structure for regions to participate in the Series Scale Competitions in order that participants may qualify for participation in the annual SA Scale Masters event which is usually held in March of every year. Furthermore, NASA has the responsibility to ensure that a Nationals for Scale is run every year, either as a Scale Nationals, or in combination with some of the other disciplines of aeromodelling. These two competitions form the basis for the selection of a National Team to represent the country every second year at the World Championships for Scale Model Aircraft, which is organised under the auspices of the CIAM of the FAI. South Africa has a proud record at the World Championships, with top five team standings in most instances and even two second team standings in 1998 and 2000.

Scale in South Africa 

Three categories of scale competitions exist, namely Sport Scale, International Stand Off Scale (F4H) and International Scale (F4C). In Sport Scale no static judging is required. The only requirement for participation is that the model must be a recognisable replica of a full size aircraft. The competition consists of three rounds of flying, of which the best two scores count toward the final result.

In F4H and F4C the competitors are required to produce documentation which is used as the basis for the determination of the static accuracy of the model. This is followed by  three rounds of flying of which the best two rounds are added to the static score achieved to determine the final score. In F4H the weight of static to flying is 1 to 2 and the requirements regarding the amount and delail of the documentation is less stringent than in F4C, whilst in F4C static and flying are equally important. 

In these two classes the documentation supplied by the competitors is used by the judges to substantiate outlines, markings, structure, surface texture, scale detail, craftsmanship and colour scheme of the subject aircraft modelled. This documentation forms a vital part of the competitor’s entry and usually consists of an accurate published three-view drawing, colour data, detailed photographs and drawings. The models which match the documentation closest will obviously be awarded the highest static scores.

The flight judging comprises assessment of the performance of the model through a series of flying manoeuvres, as well as how realistically the performance of the full-size aircraft has been duplicated. The flight schedule consists of a series of mandatory manoeuvres and a selection of optional manoeuvres that should be in keeping with the performance capabilities of the full size aircraft.
The detective work required to research a specific aircraft together with the thrill of discovery of hard to find information, the joy of creating an as perfect as possible replica, combined with the excitement of competition, is what makes this branch of aeromodelling such a worth while one.