What happened
On August 13, 2009, a Rolladen-Schneider LS 8-18, registration D-4718, departed from Pavullo nel Frignano airport as part of a group of nine gliders. The flight began with a winch launch using a Robin DR 400, registration I-ITBD, and the glider released from the tow line near Acquaria after approximately eight minutes of flight.
After roughly two hours of flight, local weather conditions deteriorated rapidly as a severe thunderstorm developed. While the other pilots in the group decided to return to the airport, the pilot of D-4718 radioed that he was approximately 6 kilometers from the airfield but lacked sufficient altitude to reach the runway safely. Consequently, the pilot attempted an off-field landing. Shortly after this communication, the glider impacted the ground in the municipality of Sestola, near Castagnola. The impact occurred at a high angle in an inverted attitude with a slight left yaw, resulting in the total destruction of the aircraft and the death of the pilot.
The investigation
The ANSV investigation examined the wreckage, the pilot's flight history, and the meteorological conditions at the time of the accident. Physical evidence at the crash site, including an impact crater and the distribution of debris, indicated a high-angle impact. The wreckage showed significant structural damage, including buckling of the tail boom and breakage of the left wing.
Investigators reviewed the pilot's credentials, noting that while he held a valid license, much of his flight experience had been accumulated between 199 and 1995. The investigation also analyzed the aircraft's maintenance records, which showed the plane was airworthy and had undergone its last annual inspection in August 2008. Medical examinations of the pilot ruled out the presence of drugs, alcohol, or pre-existing medical conditions that could have contributed to the accident.
Findings
- The primary cause of the accident was a wing stall, which likely occurred while the pilot was searching for a suitable landing site at low altitude and low speed, or while attempting a steep turn to reach a small field.
- The low altitude at the time of the stall left no margin for recovery.
- Contributing factors included an underestimation of the rapidly developing thunderstorm and the impact of heavy rain on stall speeds.
- A lack of familiarity with the specific terrain likely hindered the pilot's ability to quickly identify a safe landing area.