What aircraft was involved and where did it happen?

The accident on 2014-04-17 involved a VSO-10b, registration OK-9602, at Rájov, CZ.

What was the probable cause of the accident?

The accident was caused by the pilot's incorrect decision to alter the landing approach at a low altitude, which led to a loss of airspeed and a subsequent ground impact while maneuvering over sloping terrain.

Glider forced into field landing following loss of lift

A pilot participating in a gliding competition was forced to perform an off-field landing after failing to find rising air, resulting in a ground impact and aircraft damage.

What happened

On April 17, 2014, a pilot participating in the AZ CUP 2014 gliding competition was flying a route from Bohdaneč to Zbraslavice. While navigating the course, the pilot was unable to locate the necessary thermal updrafts, eventually entering a descending air mass with a sink rate of approximately 3 m/s.

As the aircraft's altitude decreased, the pilot identified a suitable landing area near Rájov, approximately 7.4 km southeast of Pelhřimov. However, during the final approach, the pilot attempted to change the landing decision, likely due to the influence of mechanical turbulence. This maneuver caused the aircraft to turn away from the intended landing site.

In an attempt to correct the flight path and land on an adjacent sloping field, the pilot executed a turn across the slope. During this maneuver, the VSO-10b lost airspeed and struck the ground. The impact caused the aircraft's fuselage and the right wingtip to hit the earth, followed by a bounce and a subsequent rotation. The pilot sustained no injuries.

The investigation

The ÚZPLN investigation examined the flight data recorded by the aircraft's GNSS flight recorder. The analysis confirmed that the pilot was flying at a very low altitude—approximately 30 to 70 meters AGL—when the critical decision to alter the approach was made.

The investigation also reviewed the meteorological conditions, noting that while the pilot had initially found thermals, the subsequent breakdown of cloud cover and the presence of descending air necessitated the off-field landing. The investigation also assessed the physical state of the VSO-10b, finding it to be airworthy and properly maintained, with the last annual inspection having been completed shortly before the event.

Findings

The pilot was flying a competitive task and was forced to land in a field after being unable to find rising air.
The pilot initially identified a suitable landing area but then made an incorrect decision to alter the approach maneuver.
The loss of airspeed during a low-altitude turn across a sloping field caused the aircraft to strike the ground.
The aircraft's fuselage sustained a crack, and the tail section struck the ground heavily during the impact and subsequent rotation.