What happened
On July 18, 2000, at approximately 14:15, a Glasflügel H304 glider, registration D-6203, was conducting a circuit flight when the pilot decided to perform an off-airport landing. After returning from a flight in the Mont Ventoux area, the pilot determined they could not reach the Fayence aerodrome and opted to land in a known field approximately 5 km from the airfield. This field was not equipped with a windsock.
Believing the wind was blowing from the west, the pilot approached the field on a westward final. The pilot initially touched down approximately two-thirds of the way through the field but realized the aircraft would not stop before reaching the end of the clearing. In an attempt to avoid an overrun, the pilot initiated a go-around. During this maneuver, the right wing struck a grove of trees, causing the glider to eventually come to rest in a wheat field located in a depression below the initial landing site.
The investigation
The investigation focused on the pilot's perception of the wind direction during the approach. While the pilot believed the wind was from the west, ground observations at the time of the accident indicated an easterly wind of 15 to 20 knots. Investigators examined the meteorological conditions, noting a potential confluence between a sea breeze from the east in the lower atmosphere and a westerly gradient wind at higher altitudes. Furthermore, the investigation reviewed data from a meteorological station at Mont du Lachens, which had reported a light wind from the south, a factor that likely reinforced the pilot's incorrect assessment.
Findings
- The primary cause of the accident was an erroneous evaluation of the wind direction.
- The pilot's perception of a westerly wind was likely misled by a complex meteorological phenomenon involving an easterly sea breeze at low levels clashing with westerly winds aloft.
- Meteorological data from nearby stations, which suggested a light southerly wind, may have inadvertently supported the pilot's incorrect assumption.