What happened
On September 18, 2017, a DV-1 Skylark, registration D-MMXN, was conducting a private flight from Freistadt, Austria, toward Germany. While flying near the Czech-Austrian border over the Lipno reservoir, the aircraft entered low clouds and ground fog. The high humidity caused the cockpit windows to fog and dew to accumulate on the exterior, significantly degrading the pilot's visibility.
Due to the loss of visual reference, the pilot decided to perform an emergency landing on a grassy field located between Jenišov and Horní Planá. While the landing itself was successful, the aircraft continued along the field during the rollout. During this phase, the nose gear struck a grass-covered drainage ditch crossing the field. The impact caused the nose gear fork to break and forced the propeller blades into contact with the soft terrain and tall grass, resulting in damage to the propeller.
The investigation
The ÚZPLN investigation examined the pilot's qualifications, the aircraft's maintenance history, and the meteorological conditions at the time of the incident. The investigation confirmed that the pilot held all necessary licenses and medical certifications, and that the aircraft was properly maintained and airworthy. Investigators also reviewed the weather reports from the Churáňov and Temelín stations, which indicated low visibility and heavy fog in the area during the early morning hours.
Findings
- The pilot entered meteorological conditions that were not suitable for VFR flight.
- High humidity led to the fogging and dew accumulation on the cockpit canopy, which contributed to the pilot's loss of orientation.
- The pilot likely underestimated the actual weather conditions and the developing meteorological situation during pre-flight planning.
- The pilot failed to see the drainage ditch during the landing rollout due to the severely degraded visibility through the cockpit windows.