Colisión del Ka 7 con línea telefónica cerca de Diavolezza hiere a dos

El 18 de agosto de 1962, un planeador Alexander Schleicher Ka 7 colisionó con una línea telefónica cerca de Diavolezza, Suiza. El planeador, que llevaba a un piloto y a su padre como pasajero, intentaba ganar altitud cuando hizo contacto con la línea. Posteriormente, la aeronave se estrelló contra las rocas y volcó, causando lesiones graves a ambos ocupantes. El planeador fue completamente destruido en el incidente. La investigación oficial confirmó que la colisión con la línea telefónica fue la causa principal del accidente.

1. Soaring along ridge: After a winch launch from Samedan, the Ka-7 spent about 2.5 hours soaring in the Oberengadin and was ridge-soaring near Munt Pers before returning toward the airfield.
2. Low ridge clearance: While following the ridge from Munt Pers toward the Diavolezza hut, the pilot flew past the hut with an estimated clearance of only about 25 m above the slope and 40 m from the hut.
3. Altitude lost in turn: The pilot then turned right toward Piz Palü and executed a wide, high-banked right turn of about 200 degrees over the Pers glacier margin, during which the glider visibly lost height.
4. Return low to slope: About 80 m below hut level, the pilot approached the same slope again at a shallow angle, closely following the contour lines to remain near expected lift, thereby reducing terrain and obstacle clearance.
5. Poor obstacle visibility: In the shallow, uniform scree slope with weak relief, the telephone line—spanning 15–23 m above ground and lacking nearby masts or markers—was difficult to perceive against the background.
6. Collision with cable: While turning slightly left to fly parallel to the slope, the glider struck the two-wire telephone line at about 60 degrees, damaging the canopy and left wing and causing a significant deceleration and left yaw.
7. Crash - serious injury: Approximately 60 m after first contacting the line, the glider impacted a rock band in a steep attitude, overturned, and came to rest inverted, totally destroying the aircraft and seriously injuring both pilot and passenger.