What happened
On June 2, 1968, a Ka 7 "Rhönadler" glider, registration HB-603, departed from Schänis airfield for a flight near the Schäniserberg. The flight, which included one passenger, was initially hampered by weaker-than-expected thermal conditions. After attempting to find better lift near Amden, the pilot found himself unable to return to the home airfield due to sinking air and insufficient altitude.
As the aircraft approached the area near Ziegelbrücke, the pilot began searching for suitable landing sites. While intending to land in a field west of the Schänis railway station, the pilot observed signs of rising air and diverted his path 45 degrees to the right to attempt to regain altitude. This maneuver failed to produce the desired lift, and the aircraft entered a significant sink rate. In an attempt to return to the original landing field, the pilot executed a 180-degree turn. During the final approach, the aircraft's altitude had dropped to approximately 70 meters. While attempting a right-hand turn to align with the landing strip, the pilot relied heavily on rudder rather than aileron to avoid a wing strike. This resulted in the right wing striking the ground approximately 70 meters from the railway line, causing the aircraft to cartwheel.
The investigation
The investigation examined the pilot's flight experience, the technical condition of the Ka 7 "Rhönadler", and the meteorological conditions at the time. The aircraft had recently undergone a major overhaul and was found to be in excellent technical condition, with no mechanical failures contributing to the accident. The investigation also reviewed the pilot's qualifications and the suitability of the chosen landing site, which was deemed appropriate for an off-field landing.
Findings
- The pilot's decision to deviate from the planned landing path to seek rising air depleted the necessary altitude reserves.
- The pilot failed to finalize a landing plan and terrain selection at a sufficient altitude (at least 300 meters) to allow for a proper approach.
- The final turn was executed with excessive rudder and insufficient bank, likely causing a stall of the right wing due to the aircraft's tendency to slip toward the ground.
- The pilot's experience with off-field landings was limited, though his overall training was considered sufficient for the conditions.