eric@uw-beaver (Eric Jul) (07/23/83)
Most high performance sailplanes have waterballast tanks which allow them to vary their wing loading considerably. For example, the Nimbus 3 (the hottest ship in the Open Class) can carry up to about 310 kg (approx. 680 lbs) of water ballast which may be dumped in flight to reduce the wing loading. This allows the pilot to vary AUW from about 440 kg to 750 kg. Higher wing loadings allow the pilot to achieve the same performance at higher speeds. The price paid is a greater minimum sink speed and a higher circuling radius which both mean poorer climbing ability, so there is a tradeoff. Some pilots believe that the optimum water carrying ability has been attained for most of the world championship class ships (see my comments on the results of the recent world championship). -- eric uw-beaver!eric eric@washington (arpa)