What happened
On October 12, 1968, at approximately 18:03 local time, a Rhönadler Ka 7 glider, registration HB-768, was performing a local training flight at the Eplatures airfield in La Chaux-de-Fonds. The flight was being conducted by an instructor and a student pilot. As the aircraft approached the grass runway for landing, a group of pedestrians entered the airfield area.
During the final stages of the landing, the instructor was focused on maintaining proper height relative to obstacles at the end of the runway. As the aircraft made contact with the ground, the instructor spotted a person in red clothing running across the grass. While the pilot attempted a slight leftward correction to avoid the individual, the glider struck a second pedestrian. The impact caused one fatality.
The investigation
The investigation examined the actions of the flight crew, the movement of the pedestrians, and the environmental conditions at the time of the accident. Investigators noted that the airfield was already in shadow, as the sun had set below the horizon shortly before the collision, even though the sky remained clear in the direction of the approach.
Evidence showed that the group of pedestrians had bypassed a perimeter fence and entered the airfield without authorization. While some members of the group were aware of the prohibition signs posted at the airfield, others were unaware of them. The investigation also reviewed the condition of the aircraft, noting that the cockpit canopy was significantly scratched, which may have impacted visibility.
Findings
Several contributing factors were identified during the inquiry:
- The primary cause was the unauthorized crossing of the airfield by a pedestrian, which intersected the glider's landing path.
- Reduced visibility due to the airfield being in shadow made it difficult to detect obstacles on the runway.
- The instructor's forward view was partially obstructed by the student pilot sitting in the front seat.
- The scratched condition of the aircraft's canopy further hindered the crew's ability to identify the pedestrians in time.
- The student pilot's lack of experience and intense focus on following the instructor's maneuvers likely prevented him from noticing the pedestrians until the collision had occurred.