What happened
On April 14, 2006, at approximately 10:30 UTC, a Nimbus-4M motor glider crashed on the eastern slope of the 'Guck' mountain near Kötschach-Mauthen, Austria. The pilot had departed from Lienz-Nikolsdorf airfield earlier that morning as part of a group of pilots conducting soaring flights.
During the flight, the pilot reported via radio that sufficient thermal lift could not be found near Hochstein. The last radio contact was received at approximately 10:05 UTC, and the aircraft was last visually sighted by a fellow pilot at roughly 10:15 UTC near the Kötschach ski area at an altitude of approximately 1,500 meters.
Following the pilot's failure to return to the airfield, a large-scale search operation involving helicopters and mountain rescue was launched. The wreckage was not located until April 17, 2006. Upon discovery, the pilot was found to have sustained fatal injuries.
The investigation
The investigation examined the aircraft's maintenance records, the pilot's experience, and the meteorological conditions at the time of the accident. Technical examination of the Nimbus-4M revealed no pre-existing mechanical defects; all damage was consistent with the impact with trees and the terrain. The aircraft's weight and center of gravity were within permissible limits, and all required maintenance had been performed.
Investigators also noted that while the aircraft was equipped with an automatic emergency locator transmitter (ELT), the device had not been activated during the flight, which contributed to the delay in locating the wreckage.
Findings
- The primary cause of the accident was controlled flight into terrain (CFIT).
- The pilot may have encountered strong downdrafts in the lee side of the mountain.
- Meteorological conditions featured low thermal development, which may have led to an error in judging altitude or terrain clearance.
- The pilot's ELT was not switched on, hindering the search efforts.