Flight History
On 7 May 1972, a piloted Standard Libelle glider HB-950 departed Bern at 1110 MEZ for a goal flight with return to Bern-Romont-Bern as part of the regional elimination camp (RAL) 1972. The weather featured a flat pressure distribution with thunderstorm tendencies and a low base height. During the return leg, approximately 10 km from the destination, the pilot encountered unexpectedly strong downdrafts that forced an outlanding in hilly terrain.
Accident Sequence
To shorten the landing distance, the glider touched down with the landing gear retracted at the end of an uphill meadow covered with medium grass. It then jumped over a field road that was cut about 60 cm deep into the ground, perpendicular to the approach direction. The glider struck the elevated opposite edge of the road, causing the fuselage to break behind the wing trailing edge. Subsequently, the now uncontrolled glider made a jump of about 15 meters, struck the ground with its hull in a beet field, and came to rest in normal attitude at 1320.
Damage
The pilot remained uninjured. The glider suffered heavy damage. No third-party damage occurred.
Findings
The pilot, born in 1924, held a valid glider pilot license. His total gliding experience was 2598 hours, of which 700 hours were on the accident type; in the preceding 90 days he had flown 32 hours, all on the accident type. There was no indication that his health was impaired during the accident flight.
The glider HB-950 was certified for operation and was in an airworthy condition.
The terrain at the accident site (coordinates 596.800/188.550, elevation 750 m) had few suitable landing options, and the ditch formed by the field road was barely visible from the air.
Conclusion
The commission unanimously concluded that the accident was due to an outlanding in unsuitable terrain.