What happened
On June 26, 2007, a Glaser Dirks DG 800 glider, registration D-8580, departed from the Barcelonnette aerodrome via winch launch. After a five-minute tow, the pilot released the cable at an altitude of 2,200 meters near the Bachelard ridge.
Following the release, the pilot flew along the western slope of the "Pain de Sucre" and then headed south. Due to unfavorable meteorological conditions, the pilot notified the flight center that they were changing sectors. The flight path then transitioned toward the southern slope of the "Grand Bargaud." While performing a series of right-hand turns to find lift, the aircraft struck the treetops at 10:19 UTC. The impact was severe, involving an initial strike with the right wingtip followed by a lateral collision with a second tree that struck the cockpit area, ultimately leading to the destruction of the aircraft and the death of the pilot.
The investigation
The investigation focused on the flight trajectory, local aerology, and the aircraft's technical state. Investigators utilized data from the onboard GPS and FLARM systems to reconstruct the flight path with high precision.
Analysis of the wreckage showed that the cockpit had undergone a significant rotation and that the airbrake and landing gear were deployed. No mechanical failures were identified in the flight controls prior to the impact. The investigation also examined the weather conditions, noting that while visibility was excellent, the air mass was stable with very weak thermal activity and turbulent winds caused by valley channeling.
Findings
- The primary cause of the accident was a loss of external surveillance by the pilot while maneuvering in difficult atmospheric conditions.
- The pilot was attempting to utilize southwest airflow to gain altitude through spiraling maneuvers along the terrain.
- The search for lift in weak, turbulent conditions led the aircraft to drift northward toward increasing terrain height.
- The pilot likely became overly focused on the precision of flight maneuvers to exploit minimal lift, resulting in a failure to monitor the proximity of the surrounding vegetation.
- Although the pilot was in the vicinity of the aerodrome and had the option to terminate the flight, they chose to continue in hopes of improving weather conditions.