What happened
On August 4, 2005, during a gliding competition based at Greiz-Obergrochlitz, two gliders collided head-on near Kurtschau. The first aircraft, a Schempp-Hirth Ventus CT motor glider, departed at 13:17, followed by a PZL-Bielsko SZD 48-3 Jantar at 13:34. Both aircraft were initially climbing in separate thermal currents.
At approximately 13:57, the Ventus CT exited its thermal and flew south at roughly 140 km/HD. Shortly after, the SZD 48-3 Jantar initiated a left turn, placing the two aircraft on a direct collision course. The collision occurred at an altitude of approximately 1,200 m MSL with a closing speed of about 230 km/h. The impact caused the SZD 48-3 Jantar to strike the upper surface of the Ventus CT, leading to structural failure of the Ventus CT's left wing and the detachment of the SZD 48-3 Jantar's vertical stabilizer.
Due to the severe damage, both pilots were forced to perform emergency parachute jumps. The pilot of the SZD 48-3 Jantar landed with light injuries, while the pilot of the Ventus CT sustained serious injuries during the bailout process.
The investigation
The BFU examined GPS logger data from both aircraft to reconstruct the flight paths. The investigation analyzed the visibility of the aircraft based on their apparent angular size and the physiological limitations of human perception. The investigators also reviewed the structural damage to both airframes, noting that the Ventus CT's cockpit canopy was destroyed by external impact during the collision.