Collision du Ka 7 avec une ligne téléphonique près de Diavolezza blesse deux personnes

Le 18 août 1962, un planeur Alexander Schleicher Ka 7 est entré en collision avec une ligne téléphonique près de Diavolezza, en Suisse. Le planeur, transportant un pilote et son père en tant que passager, tentait de prendre de l'altitude lorsqu'il a touché la ligne. L'appareil s'est ensuite écrasé contre des rochers et s'est retourné, causant de graves blessures aux deux occupants. Le planeur a été complètement détruit lors de l'incident. L'enquête officielle a confirmé que la collision avec la ligne téléphonique était la cause principale de l'accident.

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.