| Although experiments with rotary winged | | | | wing. |
| aircraft may be traced back to Leonardo da | | | | |
| Vinci, successful flights were not achieved | | | | The helicopter generates lift by the movement |
| until the 1930s, and it was not until 1941 | | | | of its main rotor blades through the air as |
| that the first practical, full size | | | | its rotor turns. The blades have to be moved |
| helicopter was built by lgor Sikorsky. Model | | | | at high speed and at a comparatively high |
| enthusiasts are notably quick to emulate | | | | angle of attack in order to produce |
| full-size aviation achievements, but were not | | | | sufficient lift to raise the model into the |
| as successful with rotary wing aircraft, and | | | | air. Weight is critical and experimenters who |
| it was not until 1968 that the first fully | | | | discovered that their chosen engine had |
| controllable R/C model helicopter appeared, | | | | insufficient power to produce the required |
| built by Dr. Dieter Schluter of West Germany. | | | | lift were faced with a vicious circle. |
| | | | Fitting a larger engine to increase the |
| Many modellers were convinced that the single | | | | available power also meant an increase in the |
| rotor autogiro would be an easier subject to | | | | weight to be lifted. |
| tackle than the helicopter and were | | | | |
| conducting their experiments along these | | | | Bigger engines require more fuel and more |
| lines, but in fact the first really | | | | weight! Increasing the angle of the rotor |
| successful British R/C autogiro, a semi-scale | | | | blades in the airflow produces more lift, up |
| model of the Wallace Autogiro, was first | | | | to a point but this also increases the drag |
| flown in 1978, ten years after the first | | | | of the blade, which now requires more power |
| appearance of the R/C helicopter. Designers | | | | to move it at the required speed. All |
| and manufacturers the world over were quick | | | | problems were eventually overcome and the |
| to take advantage of Schluter's success and, | | | | fully controllable R/C model helicopter had |
| In the early 1970s, model helicopter kits | | | | arrived. |
| were on sale in the model shops. | | | | |
| | | | There were, however, no short cuts in its |
| In order to appreciate the reasons for the | | | | development: engines, drive gears, rotor |
| slow development of the model helicopter, at | | | | blades, control methods, etc all had to |
| least a few of the problems which faced the | | | | follow a similar design to full-size |
| pioneers must be considered. These problems | | | | helicopter and be built to the same exacting |
| were many and complex, for instance in order | | | | standards or perhaps closer to the mechanism |
| to achieve fight with any heavier-than-air | | | | design of the full-size helicopter. |
| machine, the lift force generated by its | | | | |
| airfoils must overcome the aircraft's weight. | | | | So how difficult is the model helicopter to |
| In the case of a conventional aircraft this | | | | control in fight? Well, it has been described |
| is achieved by its forward speed through the | | | | as similar to balancing a steel ball on a |
| air which flows across its airfoil-sectioned | | | | knife edge whale riding a bicycle! more on |
| wing, causing a speeding-up of the air, and | | | | that when you visit Model Aeronautics for |
| there by a reduction in pressure, over its | | | | Dodos by following the link in my resource |
| upper surface. At the same time, pressure | | | | box. |
| increases across its under- surface of the | | | | |