Aircraft and Pilot Information
The glider involved was a Rolladen Schneider LS4, registration I-FGTM. The pilot, aged 52, held a valid Light Aircraft Pilot Licence (LAPL) and had accumulated 995 hours 56 minutes total flight time, including 678 hours 16 minutes on the LS4. The aircraft had valid maintenance checks.
Flight Details
The flight began at 07:36 UTC on 26 July 2023 from Alzate Brianza airport, with the glider released at 07:42. The intended flight was a long-duration cross-country for the Italian distance championship. The pilot had loaded 70 liters of water ballast, resulting in a takeoff mass of approximately 410 kg. Weather conditions included good visibility, no precipitation, and a northwesterly wind of 30–40 km/h.
Accident Sequence
The glider impacted terrain on the north slope of Monte Palanzone at an altitude of about 1330 m, approximately 10 m below the summit of a ridge. The last recorded data point was at 08:46:19. Prior to impact, the glider performed a series of turns: a right turn (08:44:59, 1383 m, 109 km/h groundspeed), a left turn (08:45:07, 1393 m, 91 km/h), another right turn (08:45:31, 1356 m, 81 km/h), and another left turn (08:45:47, 1374 m, 92 km/h). From 08:45:51 to 08:46:19, the glider flew a mostly straight path, losing altitude from 1376 m to 1337 m. Groundspeed fluctuated between 88 and 79 km/h. At 08:46:11, the height above ground was 23 m; at 08:46:19, it was 21 m. Impact occurred shortly after.
Pilot Statement
The pilot reported feeling fit and that the weather forecast was suitable. During the flight, he found the wind stronger than expected. He flew near Monte Bollettone and then attempted to reach Monte Palanzone. While following a ridge on the west side of Monte Palanzone at about 80 m above it and an indicated speed of 110–120 km/h, he encountered a sudden, strong downdraft near a feature called "Braga di Cavallo." This caused the glider to bank right and pitch down. The pilot maintained a nose-low attitude to avoid a stall but lost clear memory after that point. He later activated a personal locator beacon and called the departure airport, prompting a helicopter rescue.
Damage and Wreckage
The glider sustained extensive damage. The cockpit was destroyed, the right wing fractured into two parts, the vertical tail separated at the base, and the horizontal stabilizer was broken in two places with the left tip missing. The left wing was largely intact.
Probable Cause
The accident is attributable to a not sufficiently conservative evaluation of the minimum height separation from terrain: a greater margin would have allowed the pilot to regain control when an unexpected event occurred, such as a loss of lift or sudden microclimatic conditions. Contributing factors include the likely strong downdraft reported by the pilot and self-induced pressure to achieve a long-duration flight in a competition.