The desire to ski “with the wind” makes us resourceful athletes to invent a new sport: racing on skis towed behind a motorcycle (skijoring), boat and even horse. Today, it seems we are on the verge of “opening” another form of skiing-a tow sport where the athlete has to match the skills of the skier with the ability to manage a sailboat on the tires with very low pressure. Such towing is already popular among fans of winter tourism, as they allow us to travel long distances without special effort on the part of the athlete.
SKIING IN THE SAIL
Amateur designers sometimes even adulthood may surprise the naive, and young, on the contrary, thoughtful and original solutions. And as an interesting personality, whose signature is a brief article describing the construction.
In the magazine we told about the methods of choosing the parameters of the resonant pipes (“modelist-Konstruktor” No. 9 for 1995) for highly accelerated engines. Fulfilling the wishes of modelers, editors have been asked to continue this theme of the master of sports V. Fontecha from Cherkassy (Ukraine). As you know, at the time of opening of the exhaust window motor is formed as the shock wave represents the process of propagation of a pressure pulse with velocity V=20 sqr(T) (T — exhaust gas temperature in OK). 
The first control line aerobatic models that use the engine capacity of 3.5 — 7 cm3 modelers-athlete transferring from Junior level to senior championship… What it be? Youth as the original sample often chooses superprotein equipment of the world Champions or Europe and tries to copy it. In the absence of speciliaties on the model put serial domestic motor and… due to ignorance of technical and technological methods such copy get poor results and wasting time. The other extreme — a massive increase in checked malakhovich models. So there are “pilotazhki” with mediocre flight characteristics that don’t bring any sporting success.