What happened
On November 6, 1966, a Jodel D 11, registration HB-SOD, departed from Prangins for a recreational flight over the Nyon, Lausanne, and Vallée de Joux regions. The pilot was accompanied by his wife. Around 15:15 local time, the aircraft arrived over the Mollend_endruz pasture in the Vaud Jura.
While flying at an extremely low altitude—witnesses estimated between 15 and 20 meters—the pilot performed several tight left-hand circles. During these maneuvers, the aircraft was subjected to moderate to strong turbulence. Following a final turn, the aircraft headed northwest toward a pasture wall. Instead of climbing to clear a telephone line, the aircraft descended, striking the ground four meters before hitting a telephone pole. The impact severed the left wing and destroyed the engine, while the force of the crash tore the dashboard and fuel tank from the airframe. The pilot sustained fatal injuries, and the passenger suffered serious injuries.
The investigation
The investigation examined the aircraft's mechanical state, the pilot's experience, and the environmental conditions. The Jodel D 11 was found to be in good airworthy condition, with no history of significant repairs or accidents. The engine was operating normally until the moment of impact, as evidenced by the propeller damage. The pilot's medical records and post-mortem toxicology showed no impairments, and his flight experience was deemed adequate.
Investigators also analyzed the terrain and weather. At the time, a strong foehn situation was present, causing significant turbulence near the mountain slopes. The investigation noted that the telephone line was difficult to see against the snow-covered ground, though the sun's position would not have caused glare for the pilot.