Accidente del K 8 B en el bosque de Grenchenberg durante un vuelo de ladera el 18 de junio de 1972
El 18 de junio de 1972, el piloto despegó con el planeador K8B HB-884 desde el aeródromo de Grenchen. Después de 9 minutos de remolque, logró mantener su altitud mediante el planeo. Durante un giro a la izquierda, se dio cuenta de que otro K8 se acercaba, lo que provocó una rotación incontrolada hacia la derecha. El avión chocó con árboles y se estrelló en el bosque a las 1435 horas, sin que el piloto resultara herido. La investigación indicó que la velocidad inadecuada y una incorrecta maniobra contribuyeron al accidente.
- Ridge soaring flight: After aerotow from Grenchen, the pilot released at 1200 m QFE and spent over two hours ridge soaring along the south slope of the Grenchenberg at about 750 m QFE.
- Low airspeed: During the ridge flight the glider was being flown at a speed that was probably insufficient for the conditions, later estimated by the pilot at about 75 km/h.
- Traffic proximity: Approximately ten gliders were operating in the same area, and shortly before the upset the pilot encountered another K 8 at the same height about 100 m to his left on opposing course.
- Uncommanded right turn: Shortly after continuing straight ahead to avoid the opposing K 8, HB-884 suddenly rolled and turned to the right to about 30° of bank, likely influenced by a gust as reported by the pilot.
- Ineffective correction: The pilot attempted to stop the right roll with a brief control input to the left, but this did not restore normal attitude.
- Turn toward slope: The pilot then decided to continue the unintentional right turn toward the hillside, during which the glider lost height rapidly while close to the wooded slope.
- Crash - no injury: The right wingtip struck treetops and the glider crashed into the forest, heavily damaging the aircraft while the pilot remained uninjured.