What happened
On September 18, 2000, at approximately 16:00, a Glaser Dirks DG400 motor glider, registered D-KISR, was conducting a local flight after departing from Vinon airfield at 15:00. The aircraft struck the terrain on the eastern flank of the Saint-Jurs pass, located at an altitude of 1,225 meters, approximately forty meters from the ridge line.
The impact occurred while the aircraft was traveling westward on a steep descent. The wreckage was located the following day after being reported by the aircraft's co-owner. The pilot sustained fatal injuries due to the impact, and the aircraft was destroyed.
The investigation
Investigators examined the wreckage and determined that the engine remained within its housing at the time of the crash. While a GPS was present on board, its data was insufficient to reconstruct the specific flight path leading up to the accident.
Meteorological conditions at the site were characterized by winds from 250 degrees at 15 to 20 knots, with a few cumulonimbus clouds at 3,500 feet. The investigation considered several flight dynamics scenarios, including the possibility that the aircraft was caught in downdrafts on the leeward side of the terrain, or that the pilot attempted a turn at an insufficient airspeed during turbulence, leading to an unintentional autorotation.
Findings
- The primary cause of the accident was the inadequate consideration of meteorological conditions.
- The aircraft struck the terrain with a high rate of descent and a westward heading.
- The pilot was experienced, with 11,000 total flight hours, though only 10 hours had been flown in the three months preceding the accident.