What happened
On July 7, 2007, a Discus-2cT motor glider, registration D-KETE, crashed into a mountain ridge in the vicinity of Fuipiano, Valle Imagna. The flight began at Valbrembo airport, where the glider was towed by a Stinson L5. After separating from the tow aircraft at approximately 1,299 meters AMSL, the pilot spent roughly two hours utilizing thermal currents to maintain flight.
During the final stages of the flight, the pilot was performing left-hand spirals along a mountain crest. Data logs indicate that at approximately 10:41 UTC, the aircraft was in a steep left turn at a low altitude. While attempting to navigate around a rocky outcrop, the aircraft's flight path led it into a collision with the terrain at 1,476 meters AMSL. The impact resulted in the death of the pilot and extensive structural damage to the glider, including the destruction of the wings and tail section.
The investigation
Investigators analyzed data from onboard FLARM and Data Logger devices to reconstruct the aircraft's trajectory. The investigation examined the aircraft's mechanical condition, the pilot's medical and flight history, and the prevailing meteorological conditions.
Technical examinations of the wreckage showed no evidence of mechanical failure or engine malfunction prior to the impact. Meteorological reports from nearby stations and eyewitness accounts from other glider pilots indicated stable weather with light winds, though thermal currents along the mountain slopes were noted to be weak and unstable. Medical and toxicological examinations confirmed the pilot was in a fit state to fly and that no external medical factors contributed to the accident.
Findings
- The pilot was operating at very low altitudes relative to the terrain, a necessity driven by the need to exploit weak convective currents.
- The aircraft was performing a high-bank turn at low airspeed.
- An aerodynamic stall likely occurred during the maneuver, leading to a loss of control.
- The combination of the stall, the aircraft's direction toward the mountain slope, and the insufficient altitude prevented the pilot from recovering the aircraft's flight attitude.