What happened
On June 14, 1978, a Cessna 172 H, registration D-EDLQ, was conducting a private VFR flight from Ascona toward Essen-Mülheim. The aircraft was climbing through the Leventina Valley toward the Nufenen Pass. As the aircraft approached the pass, the pilot reported a sudden drop in engine power of approximately 500 RPM.
While flying in the center of the valley, the pilot attempted to execute a right-hand turn to reverse course, but found the valley too narrow to maneuver. Consequently, the pilot opted for an immediate emergency landing on a nearby snowfield. Upon impact with the upward-sloping snow, the aircraft underwent an overturn, resulting in one fatality and one injury.