LGW flight 615 departed Leipzig for Dortmund. While climbing through FL80 at an indicated airspeed of 175 knots, the plane suddenly started to swing. The crew contacted Bremen Radar and reported that they had a rudder failure. They reduced the speed to 120 knots upon which the swinging stopped. The crew decided to divert to Paderborn-Lippstadt and were cleared for a straight-in approach to runway 24. The aircraft landed safely at 18:40. On the ground it appeared that the metal sheeting of the rudder had separated completely on both sides of the rudder. The rudder had just recently been fitted with new sheeting, which had been done without using the guidelines issued by the manufacturer. PROBABLE CAUSE: “The accident is due to the fact that the procedure instructions issued by the aircraft manufacturer were not applied during the sheeting of the rudder and the measure was not carried out correctly or with the necessary care.”