What happened
On August 5, 1963, a Ka-2b Rhönschwalbe glider, registration D-9044, was performing a ridge soaring flight near Samedan, Switzerland. The flight began with a tow by a Piper Super-Cub, registration HB-OOV, into the Val Bernina. At approximately 12:15 PM, the instructor released from the tow at an altitude of 250 to 300 meters above the airfield.
While flying along the slope of the Schafberg, the glider struck an unmarked support cable belonging to the Pontresina-Schafberg material cableway. The impact occurred on the left wing, causing the aircraft to enter a spin and crash into a wooded area. Although the aircraft was destroyed, the two occupants—the instructor and a student—remained uninjured.
The investigation
The investigation focused on why the glider struck a cableway that was known to the local airfield management but not officially marked on the national aeronautical charts. Investigators found that while the cableway was not listed on the official Swiss aeronautical obstacle map, it had been recorded on a local obstacle map posted at the Samedan airfield.
The inquiry also examined the pre-flight procedures of the flight group, which was visiting from Germany for a training camp. It was noted that the flight briefing held that morning did not specifically highlight the cableway, and the pilots had not consulted the local obstacle map posted in the airfield corridor. Additionally, the investigation noted that the occupants were flying without parachutes, which was a violation of local regulations, though this was not determined to be a factor in the collision itself.
Findings
- The primary cause of the accident was the pilot's failure to identify and avoid the obstacle due to inadequate flight preparation and lack of orientation.
- The cableway's support cable was difficult to detect even in good visibility because it was unmarked and positioned against the mountain slope.
- The pilot had not reviewed the local obstacle information available at the airfield prior to departure.
- While the cableway was not on the official national aeronautical charts, it was documented on the airfield's internal notice board.