1977 Standard-Libelle HB-966 Glider Accident at Zweisimmen

Incident Overview and Flight Details On July 6, 1977, a Standard-Libelle HB-966 glider operated by the Segelfluggruppe Lenzburg crashed near Zweisimmen, Switzerland. The aircraft was on a training flight when it struck the cable of the Rinderberg gondola lift and crashed into a slope. The pilot, who had traveled to the area for a gliding camp, died shortly after the impact. The glider was destroyed, and no other damage was reported. ## Investigation and Findings The Swiss Federal Accident Investigation Commission concluded that the crash was caused by a collision with an obstacle due to insufficient altitude or a stall near a slope. Contributing factors may have included the pilot's physical discomfort, turbulence near the slope, and low-speed flight. The investigation noted that the pilot had reported feeling unwell during a previous flight and had back pain. The aircraft's weight and center of gravity were within limits, and the pilot was not under the influence of alcohol or medication. The glider's speed and altitude were not recorded, as no flight data recorder was installed.