What happened
On July 28, 1965, at the Schänis glider airfield, a Bergfalke II/55 glider, registration HB-569, was performing a landing following a series of training flights. The pilot had intended to execute a long landing near the hangars. At the same time, a group of flight students was moving across the airfield to relocate signaling equipment due to a planned change in takeoff direction.
As the aircraft touched down on the grass runway, the left wingtip struck two students who were walking approximately 25 meters from the edge of the airfield. The impact threw the students to the ground, causing injuries to both. Following the collision, the glider veered 18/0 degrees from its path, traveling approximately 40 meters before coming to a halt with heavy damage to the wing and fuselage.
The investigation
The investigation examined the movements of both the aircraft and the ground personnel. It was established that the students were not walking along the airfield boundary as instructed, but were instead moving toward the center of the field while engaged in conversation. The investigation also noted that the airfield surface was covered in puddles due to recent heavy rains, which may have caused the students to swerve.
Furthermore, the investigation looked into the pilot's visibility. In the Bergfalke II/55, the pilot's position is far forward of the wings, making it difficult to accurately judge the lateral distance between the wingtip and ground obstacles, especially during landing. The pilot had estimated a clearance of approximately 6 meters between the wingtip and the students, a margin deemed insufficient.
Findings
- The primary cause of the accident was that the pilot maintained an insufficient lateral distance between the aircraft and the students on the ground.
- The students contributed to the accident by walking significantly inward from the airfield boundary, violating established safety instructions to remain at the edge of the field.
- The presence of large puddles on the runway may have caused the students to deviate from their path at the moment of impact.
- The pilot's ability to judge the exact distance of the wingtip was hindered by the aircraft's design and the pilot's limited recent experience with this specific model.