What happened
On March 17, 2019, a Rolladen-Schneider LS 1-d glider, registration D-0787, was performing a winch launch from the S. Apollonia airfield in Castiglion Fiorentino, Italy. The flight was a recreational/sport type, with the pilot alone on board.
During the launch, the winch operator observed that the aircraft failed to establish the standard climbing pitch after liftoff. As the winch cable was released, the pilot attempted an aggressive turn to the north, likely intending to return to the runway for a landing. However, this maneuver was executed at a very low altitude and low airspeed. The aircraft entered a violent spin and impacted the ground in an agricultural field near the runway. The impact resulted in one fatality and the total destruction of the aircraft.
The investigation
The ANSV investigation examined the wreckage, the winch system, and meteorological conditions. The wreckage was concentrated in a small area, which ruled out in-flight structural failure. The winch cable and the winch mechanism itself were found to be fully functional and intact.
Investigators also reviewed the pilot's records, noting that while the pilot had recent experience with winch launches, his glider rating had expired approximately two months prior to the accident. Meteorological data from the nearby Arezzo airport indicated weather conditions compatible with VFR flight, though a crosswind component was present. The investigation also reviewed the aircraft's flight manual, specifically the procedures for winch launches, to understand the pilot's flight path.
Findings
- The primary cause of the accident was a loss of control in flight caused by an aerodynamic stall and subsequent spin.
- The stall occurred during a critical phase of flight characterized by low altitude, low airspeed, and a high-bank turn.
- The pilot's decision to execute a sharp turn likely underestimated the impact of the tailwind component, which degraded the aircraft's aerodynamic performance.
- The low altitude at the time of the maneuver left no margin for recovery.