Accidente del Blanik L-13 durante el descenso cerca de Vernamiège, Suiza, hiriendo a dos
El 13 de julio de 1975, un planeador Blanik L-13 se estrelló cerca de Vernamiège, Suiza, durante una maniobra de descenso. El piloto y su hijo estaban en un vuelo de recreo sobre los Alpes cuando el planeador entró en pérdida y se impactó contra el suelo a las 18:10 hora local. El piloto sufrió heridas graves, mientras que su hijo resultó levemente herido. La investigación concluyó que el accidente fue causado por una pérdida de sustentación durante maniobras realizadas con un margen de velocidad insuficiente. El planeador fue destruido en el accidente.
- Cruise and descent: After an aerotow launch from Sion and mountain soaring, the pilot began descending from Mont Noble toward Sion using turns and spirals along the slope.
- Low height near slope: The pilot flew spirals close to a steep hillside at relatively low height, reducing margin for error and making attitude and speed control more difficult.
- Insufficient speed margin: During these slope-side spirals the glider was flown with an inadequate speed reserve for the bank angle and conditions, increasing stall risk.
- Tightened right spiral: While completing the second right-hand spiral near the slope, the turn was tightened with increased bank and back pressure, further reducing airspeed and raising stall speed.
- Abrupt nose drop: At the end of the second spiral the glider suddenly pitched into a steep dive, consistent with an aerodynamic stall and ensuing nose-down break.
- Unrecovered descent: The glider descended steeply along the slope, slightly banked right as if continuing an impossible spiral, without sufficient height to recover.
- Crash - serious injury: The glider impacted the hillside first with the right wingtip, then the nose and left wingtip, was destroyed, the pilot was seriously injured, and the passenger slightly injured.