What happened
On June 9, 2010, a SZD-59 “ACRO” glider departed from Leoben/Timmersdorf airfield via aero-tow for a visual flight toward the Dachstein Mountains. After releasing from the tow aircraft at approximately 1,600 meters MSL, the pilot proceeded westward along the southern side of the Eisenerz Alps, eventually entering the Liesing Valley in a descent.
At approximately 10:05 UTC, the aircraft was observed performing several maneuvers at an alarmingly low altitude on the northern side of the valley between Kalwang and Mautern. The glider subsequently struck the ground in a wooded area near the Schoberpass Straße B113. The pilot sustained fatal injuries, and the aircraft was destroyed.
The investigation
The SUB investigation reconstructed the flight path using witness statements and GPS data. The investigation confirmed that the pilot held all necessary and valid licenses and medical certifications. The aircraft's maintenance records showed that the most recent annual and 100-hour inspections had been completed in March 2010, and the aircraft was within its weight and balance limits. No technical malfunctions or mechanical failures were identified, and meteorological conditions were ruled out as a cause.
Evidence indicated that the pilot had passed a suitable field for an outlanding near Kalwang but chose to continue the flight in an attempt to find rising air. As the aircraft's altitude became insufficient to return to the home airfield, the pilot likely transitioned to an approach for an outlanding at the final location.
Findings
- The pilot's decision to continue searching for lift rather than committing to an immediate outlanding left insufficient altitude for a safe recovery.
- The primary cause of the accident was a loss of control in flight (LOC-I).
- This loss of control was likely triggered by a stall resulting from the aircraft's airspeed dropping below the minimum required speed during the landing approach.