What happened
On July 25, 2008, at approximately 13:10 local time, a Rolladen-Schneider LS4A glider, registration HB-1937, was performing a winch launch from Samedan airfield. The launch was initially successful, and the aircraft reached an altitude of roughly 600 meters. After releasing from the winch cable, the pilot turned left toward the west-northwest.
While maneuvering near a steep slope at Alp Muntatsch, the glider entered a left-hand turn that brought it into contact with the treetops. The impact tore away part of the left wing, causing the aircraft to crash into the terrain approximately 60 meters downslope among trees. Although the pilot was conscious when rescuers arrived at the wreckage, he suffered catastrophic injuries. Despite intensive medical efforts and resuscitation attempts during transport to a hospital in Chur, the pilot passed away later that afternoon.
The investigation
The investigation examined the aircraft's technical condition, the pilot's experience, and the meteorological environment. The Rolladen-Schneider LS4A was found to be in good technical condition with no mechanical failures contributing to the accident. The pilot was highly experienced in the region, having flown in Samedan for 20 years, primarily using this specific aircraft.
Investigators analyzed the aircraft's weight and balance, noting that the payload was approximately 110 kg, which slightly exceeded the maximum limit of 107 kg (calculated without the tail battery). The center of gravity was likely at the forward limit. Meteorological data indicated moderate winds from the north, with witnesses noting turbulence and downdrafts in the lee of the ridge.
Findings
- The primary cause of the accident was the collision of the aircraft with a treetop during a left-hand turn near a steep slope.
- The proximity to the steep terrain made it difficult for the pilot to accurately judge the distance to the treetops below.
- The aircraft was operating in the lee of a ridge, where local turbulence and downdrafts were present.
- The pilot's flight tactics did not sufficiently account for the need for an escape maneuver when flying near the terrain.