What happened
On August 4, 2013, a Pipistrel Virus SW 100, registration D-MEKB, was conducting a flight from EDAY to EDML. While flying over the hilly terrain of the Bohemian Forest, the pilot attempted to maneuver around significant thunderstorm activity associated with an approaching cold front. During a course change near the Tachov area, the pilot reported hearing an unidentified impact against the aircraft, followed by a period of loss of control and intermittent engine performance.
Seeking a safe place to land, the pilot identified an open area near the village of Puclice. The aircraft touched down on the field, but during the subsequent rollout, the nose gear collapsed, causing the aircraft to overturn onto its back. The two occupants on board sustained only minor injuries.
The investigation
The ÚZPLN investigation examined the aircraft's technical condition, meteorological data from the Czech Hydrometeorological Institute, radar records, and witness statements. The investigation reconstructed the flight path using GPS data and ATS radar tracks.
Investigators analyzed the weather conditions at the time of the accident, noting that while the pilot reported clear skies and light winds during landing, meteorological records indicated the aircraft was operating within a highly turbulent environment characterized by a cold front, heavy rain, and strong wind gusts. The commission also examined the aircraft's wreckage, noting significant damage to the wings and landing gear, but found no evidence of a bird strike or mechanical failure in the flight controls.
Findings
- The pilot's decision to fly along the leading edge of a cold front placed the aircraft in an area of intense turbulence and wind shear.
- The reported impact and subsequent engine irregularities were likely caused by severe turbulence and rapid changes in load factors, which may have disrupted fuel delivery.
- The pilot's choice of landing site was inappropriate, as the aircraft was approximately 1.5 km from the much closer LKSA aerodrome.
- The aircraft likely landed with a significant tailwind component, which contributed to the extended rollout and the eventual collapse of the nose gear.
- Discrepancies were noted between the pilot's account of the weather and the actual meteorological conditions recorded at the time of the accident.