What happened
On April 3, 2014, at approximately 11:22 UTC, a Schleicher ASH 26E glider was performing a local flight in the vicinity of the Hohen Wand mountains in Lower Austria. The flight originated from the Wr. Neustadt-West airfield. The pilot was flying at a low altitude in the area when the aircraft suddenly banked to the left.
According to a witness flying a nearby glider, the aircraft's wings briefly flashed in the sunlight, which was interpreted as the onset of a spin. The aircraft then disappeared from view and struck a steep mountainside approximately 2 km north of the village of Oberhöflein. The impact, which occurred after roughly one and a flight of approximately one and a half turns, resulted in the death of the pilot and the total destruction of the aircraft.
The investigation
An investigation by the Austrian SUB examined the wreckage, flight data logger, and witness testimony. Investigators confirmed that the aircraft's maintenance was up to date and all required documentation was valid. The aircraft's weight and center of gravity were within permissible limits for the flight.
Analysis of the wreckage showed that the engine, landing gear, and spoilers were all retracted and locked. While the camber control lever was in the position for thermal flight, it was not locked in place; however, investigators could not determine if this was due to pilot action or the impact itself. The flight data logger confirmed the sequence of the left-hand turn and the subsequent loss of control. No pre-existing technical defects were found in the control surfaces or the airframe.
Findings
- The aircraft was operating at a low altitude over ground, leaving no margin for recovery.
- The pilot allowed the aircraft to drop below the minimum flight speed.
- The primary cause of the loss of control was the influence of thermal air currents (thermics), which likely induced a stall or sudden change in angle of attack.