What happened
On June 10, 2017, at approximately 16:00 local time, a training flight was underway at Buochs airfield (LSZC). The pilot was operating an LS-4b glider, registration HB-3144, with the objective of performing thermal soaring near the Rigi mountain. Following the initial portion of the flight, the pilot returned to the airfield and began preparing for a landing on runway 06.
During the approach phase, the wind conditions were characterized by variability and side-wind components. A flight instructor, who was nearby in a dual-seat training glider, observed the conditions and advised the pilot to increase airspeed to compensate for the wind. While the approach initially appeared normal, the variable headwind caused the final approach to become unstable. Just before reaching the threshold of the runway, the aircraft struck the pavement. The impact caused the glider to bounce back into the air before eventually coming to a stop on the ground adjacent to the runway.
The investigation
Investigators examined the flight sequence and the environmental conditions at the time of the incident. The investigation focused on the transition from a stable approach to the unstable state encountered just before touchdown. The assessment included the aircraft's mechanical condition and the impact of the wind components on the flight path.
Findings
- The aircraft sustained significant damage, including a tear in the fuselage tube and various scratches on the nose and the right wing.
- The primary contributing factor was the unstable approach resulting from fluctuating wind speeds and directions.
- There were no injuries to the pilot or any third parties involved in the incident.