Crash du Blanik L-13 lors de la descente près de Vernamiège, Suisse, blessant deux personnes
Le 13 juillet 1975, un planeur Blanik L-13 s'est écrasé près de Vernamiège, Suisse, lors d'une manœuvre de descente. Le pilote et son fils effectuaient un vol de loisir au-dessus des Alpes lorsque le planeur a décroché et a percuté le sol à 18h10 heure locale. Le pilote a subi des blessures graves, tandis que son fils a été légèrement blessé. L'enquête a conclu que l'accident a été causé par un décrochage lors de manœuvres effectuées avec une marge de vitesse insuffisante. Le planeur a été détruit dans le crash.
- 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.