The pilot was conducting a soaring flight when deteriorating lift conditions made an outlanding necessary. A paddock was chosen and the pilot carried out a standard approach pattern, aiming to land into wind. He noted a powerline pole on a hill some 500 metres away, but could not see any other poles near the intended landing area. However, as he was about to turn onto final approach, he noticed a single powerline directly ahead of the aircraft. There was insufficient time available to take any avoiding action, and the wire struck the aircraft canopy. The aircraft subsequently impacted the ground and cartwheeled to a stop 87 metres beyond the point of collision with the wire. The powerline struck by the glider was particularly difficult to see from the air. The pole on the hill was prominent, but the other pole was situated amidst a group of farm buildings. The distance between the poles was one kilometre. The pilot had been at a lower height than normal for a turn onto final approach, however there was little doubt that the intended landing would have been successful had the wire been avoided.