What happened
On July 26, 2023, at approximately 08:46 UTC, a Rolladen Schneider LS4 glider, registration I-FGTM, crashed on the northern slope of Monte Palanzone, Italy. The pilot was participating in a long-distance flight as part of the Italian distance championship, having departed from Alzate Brianza airport earlier that morning.
While flying along a ridge near the "Braga di Cavallo" area, the pilot encountered a sudden and intense downdraft. This unexpected atmospheric phenomenon caused the aircraft to pitch down and bank sharply to the right. The glider struck the terrain at an altitude of approximately 1,330 meters, resulting in serious injuries to the pilot and extensive damage to the aircraft. The wreckage showed a destroyed cockpit, a fragmented right wing, and a broken horizontal stabilizer.
The investigation
The ANSV examined the wreckage, flight data from an onboard LX 7007 flight recorder, and the pilot's testimony. The flight recorder data confirmed a series of turns in the minutes preceding the impact, followed by a steady loss of altitude and groundspeed.
The pilot reported that the aircraft had been prepared with 70 liters of water ballast to handle expected winds. Although the pilot noted a North-West wind of 30–40 km/h, the specific downward air current encountered was unexpected given the local topography and the pilot's extensive experience in the area. The pilot also noted that while they could have maintained a higher altitude, the intensity of the microclimatic event was unpredictable.