What happened
On June 28, 2020, a pilot operating an L 13 A Blaník, registration OK-9722, departed from Křižanov airfield for a thermal flight. After approximately one hour of flight, the pilot was unable to locate a sufficient rising air current. Due to the significant distance from suitable airfields, the pilot decided to terminate the flight and perform a landing in the terrain.
While searching for lift, the aircraft' and altitude decreased significantly. The pilot eventually identified a large field southeast of the village of Rousměrov as the most suitable landing site, noting that surrounding areas were either heavily forested, contained high-voltage power lines, or featured unsuitable crops like sugar beets. The pilot approached the field, aiming for a relatively level and low-growth area to avoid obstacles.
During the landing maneuver, the glider touched down in a field containing tall, standing grain. The impact of the tall crop against the aircraft's structure caused the destruction of the horizontal stabilizer and extensive damage to the rear fuselage, specifically affecting the area around bulkhead number 15 and the rear part of the fuselage.
The investigation
The ÚZPLN investigation examined flight data records, meteorological reports from the Czech Hydrometeorological Institute, and the pilot's account. The investigation also reviewed the aircraft's maintenance history and the physical condition of the wreckage. The investigation confirmed that the pilot held valid licenses and medical certification, and that the aircraft was airworthy and properly insured. The investigation also noted that the pilot had limited experience with thermal soaring and had no prior experience with off-field landings.
Findings
- The primary cause of the accident was the impact of the horizontal stabilizer against the tall grain crop during the landing.
- The pilot's decision to land in the field was driven by the lack of available thermal lift and the presence of hazards (trees, power lines, and unsuitable crops) in the surrounding terrain.
- The pilot's experience in thermal flight and off-field landings was limited.
- The aircraft sustained significant structural damage to the tail section due to the height of the crop.