Summary
The accident occurred on 14 August 1967 at 1558 local time, approximately 400 meters southeast of Schänis airfield in the canton of St. Gallen. The glider, a Rhönlerche II registered HB-807, was substantially damaged, and the student pilot sustained minor injuries treated on an outpatient basis.
Aircraft Information
The Rhönlerche II HB-807 was owned and operated by the Alpine Segelflugschule Schänis AG. Its airworthiness certificate was valid, and no evidence of pre-existing mechanical issues was found.
Pilot Information
The pilot, born in 1949, held a valid learner permit for gliders. His total flying experience amounted to 6 hours and 2 minutes over 54 flights, all but one of which were conducted on the Rhönlerche II.
Weather and Terrain
At the time of the accident, visibility was about 10 kilometers, with 8/8 cloud cover at approximately 2000 meters above field level. Temperature was around 20°C, and a light southeasterly wind was blowing. The accident site was in the approach sector to runway 35, about 400 meters from the threshold. A high-voltage power line crossed the approach path perpendicularly.
Sequence of Events
On the day of the accident, the student had already completed one of three required solo cross-country flights for the glider pilot license. After that flight, the instructor assigned him another soaring flight of at most 45 minutes, with the instruction to abandon slope soaring by 500 meters above field level. The student took off at 1547 hours on an aerotow and released at 600 meters above field near the Schäniserberg, heading towards Kaltbrunn. After a turn, he flew towards Ziegelbrücke but failed to find lift. When he reached an altitude of 350 meters above field near the ridge rising from that village, he realized he could not make it back to the airfield. Still, he flew towards the field and then saw that he could not clear the power line crossing the approach sector. He decided to execute a right turn to land parallel to the line in a meadow. His airspeed was about 50 km/h. During the turn, he pulled the stick slightly and noticed the glider no longer responded to controls, then it stalled and dropped over the right wing. The glider struck the ground at a fairly steep angle and was substantially damaged. The pilot suffered minor injuries treated on an outpatient basis.
Discussion
According to the instructor's orders, the student should have been towed to 700 meters above field and terminated the flight by 500 meters. However, he released at 600 meters even though no lift was available, leaving only about one minute to search for lift. He decided to return to the airfield only when he was at 350 meters near Ziegelbrücke, which was too late. Subsequently, he saw he could not clear the power line. The inexperienced pilot was flying at no more than 50 km/h, near the minimum speed. During the turn, he pulled the stick, causing the glider to stall and drop over the right wing. The altitude was too low to recover, and the glider impacted the ground.
Conclusion
The accident was caused by the student's late decision to return to the airfield, necessitating an off-field landing, during which, on the final low turn, he undershot the minimum speed, causing the glider to stall.