What happened
On July 1, 2015, at approximately 16:30 local time, an LS8-18 glider, registration HB-3364, collided with steep, rocky terrain at Chlein Seehorn in the municipality of Klosters-Serneus. The aircraft was participating in the 2015 Junior Swiss Gliding Championship, performing a competitive cross-country task.
The flight began with a tow from Schänis airfield. After releasing from the tow plane, the pilot navigated through various turning points. While the flight was initially efficient, the pilot eventually decided to divert from the intended route toward the Engadin valley, heading back toward the Prättigau region instead. During this phase, the aircraft struck the western flank of the mountain at an altitude of approximately 2,984 meters. The impact was severe, causing the complete destruction of the cockpit and breaking both wings and the fuselage. The pilot sustained fatal injuries due to polytrauma caused by the impact.
The investigation
Investigators from SUST reconstructed the flight path using Flarm data from other nearby competition aircraft, as the onboard GPS was destroyed during the crash. The investigation examined the pilot's flight history, noting that while the pilot was highly regarded by peers for being a reliable and cautious flyer, his specific experience in high-alpine environments was limited. Most of his recent training had taken place in the region of Amlikon and southern Germany.
The investigation also looked into the aircraft's equipment. Although the glider was equipped with a 406-MHz emergency locator transmitter (ELT), the device failed to transmit a signal because the impact tore the antenna from its mount and a defect in the switch caused the internal contacts to remain in the "off" position. Furthermore, the search and rescue process was delayed because the aircraft was not reported as overdue until several hours after the accident occurred.
Findings
- The primary cause of the accident was a collision with steep, rocky terrain.
- The specific reason the aircraft entered into the terrain could not be determined.
- The pilot's limited experience with alpine flying may have contributed to the accident.
- The unusual pressure of a competition environment, which was a new situation for the pilot, may have played a role in the occurrence.
- There were no evidence of pre-existing technical malfunctions in the aircraft.
- The delay in reporting the aircraft as overdue hindered the initial search efforts.