What happened
On April 19, 1965, a student pilot was performing a training circuit via winch launch at the Amlikon airfield. During the takeoff roll in the S-1elog S-19 (HB-240), the left wingtip made contact with the ground, causing the aircraft to veer to the left.
Believing the aircraft could be stabilized without intervention, the pilot attempted to correct the deviation using full aileron and rudder input. However, the aircraft lifted off the ground and entered an abnormally steep climb. Because the aircraft remained attached to the winch cable near its center of gravity, it began a slow rotation to the right, resembling a renversement maneuver. At an altitude of approximately 30 meters, the pilot finally released the cable, at which point the glider entered a dive. The aircraft struck the ground at an angle of 30 to 45 degrees, hitting the right wingtip first and spinning 110 degrees before coming to rest destroyed.
The investigation
The investigation examined the aircraft, the pilot's experience, and the environmental conditions. The S-19 was a single-seat, high-wing wooden glider. Technical inspections revealed no mechanical defects; however, the aircraft was noted for having heavy aileron controls and a tendency to oscillate around the vertical axis during abrupt rudder inputs. The pilot was a student with approximately 16 hours of flight experience. Weather conditions at the time of the accident involved light turbulence and overcast skies.
Findings
- The pilot failed to follow the established safety rule to immediately release from the winch cable following any irregularity during the takeoff roll.
- The failure to release the cable after the wingtip touched the ground allowed the aircraft to enter a dangerous, abnormal flight attitude.
- The pilot's focus on correcting the lateral deviation with control inputs likely distracted them from the necessity of pushing the control stick forward to manage the pitch.