What happened
On July 7, 2016, during the 3rd Unofficial Czech Republic Two-Seater Glider Championships, an L 23 SUPER-BLANÍK, registration OK-0202, was participating in a competitive flight task. While returning to the airfield at Dvůr Králové nad Labem (LKDK), the pilot encountered a lack of rising thermals, causing the aircraft to lose sufficient altitude to complete the prescribed mission.
As the aircraft approached the area of Brzice, the pilot was flying at an altitude of less than 200 meters AGL. In an attempt to locate rising air, the pilot performed several 360-degree turns. During these maneuvers, the altitude dropped significantly, reaching approximately 30 meters AGL. The pilot selected a field for a forced landing, initially believing the crop was either low-lying or grass. However, as the aircraft leveled out for touchdown, the pilot realized the corn was much taller than anticipated. The left wing struck the tall corn stalks, causing the glider to veer and the wing to deform.
The investigation
The ÚZPLN investigation examined flight data from a GNSS flight recorder, which tracked parameters such as altitude, sink rate, and airspeed in 5-second intervals. The investigation also reviewed pilot statements, competition organizer reports, and the local police findings.
Investigators analyzed the flight path, noting that the pilot had flown over populated and uneven terrain at very low altitudes. The investigation also assessed the aircraft's condition, finding that the left wing had sustained structural damage, including a bent wing spar and a cracked composite wingtip, while the rest of the airframe remained intact. The meteorological conditions at the time were examined, confirming that while the weather was generally suitable for flying, the loss of convective activity necessitated the early termination of the flight.
Findings
- The primary cause of the accident was the pilot's decision to search for rising air instead of performing a timely forced landing in a safer location.
- A contributing factor was the unexpected height of the corn crop at the specific touchdown point, which the pilot had misjudged from a distance.
- The pilot was fully qualified and the aircraft was airworthy at the time of the incident.
- No injuries were sustained by the two crew members.