What happened
On July 2, 1962, a Boclan glider, registration HB-646, was participating in a local training flight near Saint Jean en Royans, France. The aircraft, operated by the Geneva section of the Aéro-Club de Suisse, was being towed by a Champion aircraft, registration HB-UAN, to scout for thermals along the mountain slopes.
After the glider was released from the tow plane at an altitude of approximately 550 meters, the crew proceeded to fly toward the mountain massif. According to the surviving pilot, the aircraft flew normally for several minutes. However, as the glider approached the ridge, it entered a spiral at an insufficient airspeed. The pilot reportedly alerted the occupant in the rear seat to the low speed, but the aircraft subsequently entered a stall while flying with a tailwind. The glider then plummeted vertically into a dense forest.
The investigation
Local authorities and investigators examined the wreckage at the Col de Gaudissard. The investigation established that the aircraft struck the ground with significant force, as the dense tree canopy failed to arrest its descent. During the impact, the cockpit area struck a large oak branch approximately four to five meters above the ground.
Findings
- The impact of the occupant's head against a tree branch during the descent caused fatal injuries to the rear occupant.
- The pilot sustained only minor contusions.
- The Boclan glider was a total loss, with the fuselage and cockpit completely destroyed.
- The primary cause of the accident was attributed to pilot error resulting in a loss of airspeed and a subsequent stall.