Genijus ar idiotas?

Skaitinejau angliska foruma ir radau linka i sita: http://www.paraglidingheadquarters.com/articles.html#Can_we_trust_the_numbers Pradejau skaityti ir labai suintrigavo keli autoriaus teiginiai. Ypac dalis po “Myths and Physics” kur kalbama apie pasukima. Tiems kas sunkiai skaito angliskai trumpai paaiskinsiu: Tradicinis mokymas yra kad posukis daromas traukiant vidine klevanta ir permetant svori i posukio vidu. Autorius sako kad svorio permetimas i vidu yra zalingas nes svori reikia deti toje konsoleje kurioje norime matyti didesni greiti (isoreje!). Jis eksperimentavo ir rado buda kad inicijuojant posuki reikia mesti i vidu (kaip ir tradicinis posukis), bet posukiui prasidejus reikia permesti i isore kad ikrauti ta konsole kuriai posukyje reikia skristi greiciau. Momentas, kuriuo ta perkelima reikia padaryti yra labai svarbus ir turi buti atidirbtas.

Ka manote apie tokia teorija?

Cituoju angliska teksta apie posuki:

“Weight shifting in the direction of turn will make turning more efficient.” This belief survived about 2 decades and only the birth of Acro Paragliding put some doubts on it. Acro pilots need to turn more efficiently and safely than CX pilots. They discovered soon, the accepted technique doesn’t work in all situations. If you look at the mechanics of it, you’ll easily understand why: In a turn, you want the outer wing to fly faster than the inner one. In order to make it fly faster, you need to put more load on it. Furthermore, you want to maintain the correct angle of attack. If you reduce the load at a given speed, angle of attack will get lower and the wing will eventually tuck. The inner wing, on the contrary, has to fly slower and you can guess: loading it more doesn’t exactly help the cause. We also want it to stall as late (at as low speed) as possible. A funny thing… the higher the loading, the higher the stall speed is. So, now: why, for god’s sake, should you transfer more weight to the inner wing? Possibly to bank the wing into the turn… Do you really think you can bank (to any significant degree) a wing with a strong pendular stability by weightshifting? If there is no any other force but gravity (straight flight), you will aways hang straigh down, wighshifting or not. Bank will come as result of the turn (certifugical force), it will not cause it.
Despite of the mechanics of it was clear to me from the day one, it took me almost 2 years to learn the new technique and find it perfectly natural. The reason it took so long: I believe we have some instincts inherited from riding a motorbike. Takes a while to get over it. At this stage I apply more weight in the direction of the turn only for a brief period needed to initiate the turn and associated bank. Why it is needed and why it works at all is a bit of a puzzle. I discussed this phenomenon with some highly involved people. Nobody was able to give me a full explanation. The whole thing seems to be several factors working together (or against each other). Changes in the shape of the wing seem to be one of them, but I wouldn’t try to elaborate on this problem myself. The final result depends on the proportion of each of the factors involved and it may not be the same with different wings and in different situations. Anyway – from the point of initiation of the turn I transfer my weight immediately to the outside wing while braking on the inside – and bingo: everything works exactly the way the theory says. A word of warning: Timing is an important part of the equosion and it may not work for you until you master it properly. However, when you once do it right, you’ll recognize it right away. Once having it right you can get results you never thought possible before. Applied during a spiral you go down more than 20m/s during the second turn. In a wingover you’ll find yourself above the canopy before you know it. Do NOT use this technique for any kind of radical maneuvers unless under supervision of an instructor and in a safe environment (above water). For improving the efficiency of your “normal” turns however, it is perfectly safe. Tuck of the outside wing will become a history and negative spin will be harder to induce. Do not push it too far though and discuss the matter with your favourite instructor before trying at home.