What happened
On July 10, 2014, a private Schempp-Hirth Ventus 2CM glider, registered HB-2298, departed from the Sisteron Vaumeilh aerodrome for a local flight. During the flight, the pilot communicated with another aircraft, noting that they had reached an altitude of approximately 4,000 meters.
At approximately 17:00, a ground witness reported hearing a cracking sound and observed the glider descending in a spin with one wing missing. The aircraft was at an altitude of roughly 200 to 300 meters when the failure occurred. The detached section of the wing was recovered approximately 1,200 meters from the main wreckage. The accident resulted in one fatality and the total destruction of the aircraft.
The investigation
Investigators examined the wreckage and found that the right wing had failed due to an upward bending overload between the wing root and the airbrake well. Technical inspections of the materials and bonding processes revealed no manufacturing defects or structural flaws. The flight controls were found to be fully functional. The flap control was positioned at -2 degrees.
Meteorological analysis indicated the presence of a mountain wave, evidenced by lenticular clouds. While turbulence was generally weak above 1,800 to 2,500 meters, significant wind speeds (25 to 30 knots) were present between 1,500 and 3,000 meters. The investigation also noted that the onboard flight recorders were too heavily damaged to retrieve data. Additionally, while the pilot was using oxygen cannulas, the oxygen bottle and regulator were not recovered from the site.
Findings
- The right wing failure was caused by an upward bending overload.
- This structural failure was likely the result of a loss of control or abrupt control inputs while flying at high speeds.
- The pilot may have entered cloud cover, potentially leading to spatial disorientation due to a lack of external visual references.
- The possibility of altitude-induced hypoxia could not be ruled out, as the amount of oxygen available during the flight was unknown, though hypoxia remains a critical risk during high-altitude operations.