Accident
On 4 July 1966, a Schleicher Ka 8 B sailplane, registered as HB-663, was involved in an accident while attempting to land at a military airfield located in an Alpine region. The pilot of the glider encountered difficulties returning to the departure airfield due to a lack of thermal updrafts. During a close approach that required crossing obstacles, the glider entered a group of trees and sustained damage.
Investigation and Findings
The official investigation by the Swiss Federal Air Accident Investigation Commission concluded that the absence of rising air currents (thermals) hindered the pilot's ability to return to the starting point. As a result, the glider's approach became tight, and it collided with trees. The report notes that the glider was damaged in the incident. No further details regarding the extent of damage, injuries, or other factors were provided in the findings.
Probable Cause
The investigation report did not explicitly state a probable cause for the accident, but described the sequence of events: lack of thermal updrafts led to difficulty returning to the airfield, and during a tight approach over obstacles, the glider struck trees.