What happened
On November 2, 2014, at 10:21 UTC, a Nimbus 2 glider, registration HA-4540, struck 22 kV overhead power lines near the village of Bukovice, approximately 11 km SSW of Mikulovice Airport (LKMI). The pilot was participating in the "Wave Camp 2014" international gliding event and was attempting to locate thermal lift near the Jeseníky mountains.
After releasing from a towplane at approximately 751 meters, the pilot was unable to establish contact with any rising air currents. As the glider's altitude steadily decreased, the pilot searched for thermals along the western slopes near Domašov and later near Bukovice. Having lost sufficient altitude, the pilot decided to perform an emergency landing at the Bukovice landing field. During the final approach, while flying at a low altitude of approximately 50 meters AGL, the glider's right landing gear housing struck the upper phase conductor of the power lines. The impact severed the wire and caused the glider to strike the ground and a wire fence supported by concrete posts. The pilot sustained one minor injury.
The investigation
The ÚZPLN investigation examined the aircraft's GPS flight data, witness statements, and the physical wreckage. The investigation confirmed that the pilot was fully qualified and the aircraft was airworthy. Investigators analyzed the flight path, noting that the pilot had sufficient altitude and a viable landing area available much earlier in the flight. The investigation also reviewed the meteorological conditions, which included clear skies and high temperatures, and the visibility of the power lines relative to the sun's position during the approach.
Findings
- The primary cause of the accident was the late commencement of the landing maneuver, which resulted in insufficient altitude to clear obstacles.
- A contributing factor was that the overhead power lines were likely difficult to see clearly due to the pilot's approach being positioned obliquely against the sun.
- The pilot's continuous descent while searching for thermals led to the approach being conducted at an altitude too low to safely avoid the 22 kV lines.