Tacke Windtechnik has replaced the 20 metre blades on a number of its 600 kW turbines after another blade failure, this time at Neuküstrinchen in Brandenburg in April. The company refuses to specify how many blades have been replaced, but there are nearly 300 Tacke 600 kW machines registered as operating in Germany, according to statistics of wind produced energy published by Windpower Monthly's sister publication, WindStats. The 600 kW is Tacke's most sold turbine. An earlier failure of a blade on a Tacke 600 kW unit occurred at Kamen in North Rhine Westfalia in February when the blade snapped along its spar. This blade was made by Tacke's factory in Canada. The failed Neuküstrinchen blade was made by Tacke in Germany. Before starting its blade replacement programme, Tacke invited the operators of all 600 kW turbines equipped with 20 metre blades to its headquarters in Salzbergen to explain the problem and co-ordinate blade replacement. According to Tacke's Hartmut Zöpke, the failures are due to errors in the manufacturing process, which has since been modified and improved.