What happened
On November 3, 2007, at approximately 14:40 UTC, a Schempp Hirth Nimbus 2 glider, registration I-ANKA, was performing a recreational flight at the Molinella aerodrome in Italy. The flight was being conducted via aero-tow, with a C305 aircraft serving as the tug plane.
During the initial takeoff roll, the glider began oscillating vertically, failing to maintain the optimal position behind the tow aircraft. After traveling roughly 100 meters along the ground, the glider rose to an estimated altitude of 45 meters above the tug. Although the glider eventually stabilized its position, the tow aircraft subsequently experienced an uncommanded pitch-down and a left yaw. Due to the low altitude, the tug pilot elected to release the glider and perform an immediate landing.
Following the release, the glider pilot attempted to return to the runway. However, the pilot lost control of the aircraft, which entered a stall just meters above the ground. The glider impacted the edge of the runway in a nose-down attitude with a rightward rotation. The pilot sustained a broken right leg and various contusions, while the Schempp Hirth Nimbus 2 was destroyed.
The investigation
The ANSV investigation examined the wreckage, ground impact marks, and testimonies from both the glider and tug pilots. The investigation confirmed that the glider struck the ground in a nose-down, rotating attitude with limited energy due to the low altitude. The investigation also verified that the tug pilot's account of the instability and the subsequent release of the glider was consistent with the physical evidence. No technical malfunctions were identified in the glider's systems.