What happened
On June 29, 2019, a Standard Cirrus glider, registration OK-0783, was participating in the second day of a glider competition near Rajcza, Poland. The pilot was flying a course that originated from Frýdlant nad Ostravicí, Czech Republic. During the flight, the pilot attempted to cross mountainous terrain but was unable to find sufficient thermal lift to maintain altitude over the Beskyd mountains.
As the pilot searched for suitable landing sites, they found that most nearby fields were unsuitable due to fences or overhead power lines. The pilot eventually identified a field with tall grass. Due to the presence of houses and trees on the approach path, the pilot opted for a high-speed approach to maintain a safety margin against potential gusts. To lose altitude quickly, the pilot utilized full airbrake deployment, increasing the airspeed to approximately 140 km/h.
Upon touchdown in the tall vegetation, the glider experienced a sudden braking force that caused the aircraft to rotate approximately 180 degrees around its vertical axis. The glider then slid backward, resulting in structural damage to the wing, wingtips, and center spar. The pilot was uninjured.
The investigation
The ÚZPLN investigation examined the flight data from an onboard LXNAV NANO 3 flight recorder and reviewed maintenance records. The investigation established that the pilot was fully qualified and the aircraft was airworthy. Analysis of the flight recorder confirmed that the descent rate increased significantly during the final stages of the approach, with the pilot accelerating the glider to high speeds to clear obstacles before leveling out at approximately 15 meters A<span style="text-decoration:none">AGL</span>.
Findings
- The pilot was unable to find sufficient thermal lift to clear the mountainous terrain.
- The decision to land in a field of tall grass was made after other nearby options were deemed unsafe due to obstacles.
- The final approach was conducted at a high airspeed to ensure a safety margin near trees and buildings.
- The primary cause of the accident was the late decision to find a suitable landing site, which resulted in landing in tall grass.
- The contact between the wing and the tall vegetation induced the rotation and subsequent structural damage.