What happened
On August 20, 2011, a Schempp Hirth Janus B glider, registration F-CFAU, departed from the Sainte-Foy-la-Grande airfield for a local flight. The flight was carried out with a pilot and one passenger. Approximately ten minutes into the flight, the pilot determined that the tow aircraft's climb performance was insufficient and requested a return to the airfield to release the tow and land.
The release occurred at an altitude of 200 meters, roughly 800 meters from the threshold of runway 10. During the final approach, the pilot observed an unusually high rate of descent despite having the airbrakes retracted and the flaps set to 0°. Unable to arrest the descent, the glider struck a bramble hedge located before the runway threshold. The aircraft pivoted upon impact and came to a halt within the airfield perimeter. The impact resulted in a broken tail boom.
The investigation
The investigation examined the meteorological conditions and the pilot's awareness of local weather changes. While the pilot's pre-flight briefing indicated no significant aerological phenomena and the pilot believed the wind was calm during the final approach, investigators looked into broader weather patterns.
Météo France records indicated that a line of thunderstorms located approximately 15 nautical miles from the Atlantic coast caused a temporary wind shift to the northwest near Saint-Émilion at approximately 14:30. This shift occurred within the timeframe of the glider's landing attempt.
Findings
- The primary cause of the accident was the pilot's failure to detect a change in aerological conditions between the time of takeoff and the landing attempt.
- The pilot performed the approach with a tailwind, which was not anticipated based on the initial flight briefing.
- The lack of information regarding nearby thunderstorms in the glider flight bulletin meant the pilot was not alerted to the potential for sudden wind direction changes.