Accidente del SZD-30 Pirat en Zweisimmen tras intento fallido de vuelo de ladera
El 22 de agosto de 1987, un SZD-30 Pirat se estrelló cerca de Zweisimmen, Suiza, resultando en la muerte del piloto. El piloto intentaba un vuelo de distancia FAI de 50 km bajo excelentes condiciones térmicas. Después de ser liberado del remolque, el vuelo procedió con normalidad hasta que el planeador encontró dificultades cerca de Fromattgrat. Había fuertes ráfagas de viento y turbulencias en la zona. El accidente se atribuyó a tácticas de vuelo inadecuadas a lo largo de la ladera, agravadas por factores como la turbulencia, la poca experiencia de vuelo y la posible fatiga.
- Cross-country thermaling: After an aerotow launch from Gruyère and release over the Schopfenspitze, the pilot conducted a normal cross-country soaring flight via Gros Mont, Gastlosen, Spillgerten and Stockhorn under good thermal conditions.
- Low, turbulent ridge thermaling: Near the Fromattgrat ridge above Zweisimmen, the pilot began circling along the slope in strong southwesterly gusts and turbulence while having difficulty gaining height.
- Low terrain clearance: The glider was flown in close proximity to the sloping terrain, with a probable misjudgment of distance to the ground during ridge circling.
- Limited experience and fatigue: The pilot had relatively low overall and pre-alpine experience and may have been physically fatigued after about 2.5 hours of flight, possibly influenced by a low level of alcohol in his system.
- Continued tight circling: The pilot continued to circle at least three times along the ridge in the turbulent conditions instead of breaking off to a safer height or terrain clearance.
- Loss of safe margin: While circling close to the slope in turbulence, the glider lost its remaining safety margin to the terrain and descended toward the hillside.
- Crash - fatal: The glider impacted almost perpendicularly into the 25° grass slope at about 2007 m near the Fromattgrat, was destroyed, and the pilot sustained fatal injuries.