What happened
On July 1, 2012, during the SAFARI 2012 competition near Choustníkovo Hradiště, two gliders collided in mid-air while searching for thermal currents. The first aircraft, a Standard Cirrus CS 11-75 L with registration OK-2666, was flying in a right-hand turn at approximately 940 meters altitude. Simultaneously, an SZD 48 Jantar Standard 2, registration OK-5259, was performing a left-hand turn in the same area.
Between 13:56:24 and 13:56:32, the flight paths of the two gliders intersected. The Standard Cirrus CS 11-75 L struck the right wing of the SZD 48 Jantar Standard 2 from the rear and below. The impact shattered the cockpit canopy of the OK-2666, causing the aircraft to enter an uncontrollable dive. Faced with the loss of control, the pilot of the OK-2666 unbuckled his harness and exited the cockpit, deploying his parachute. He landed safely in a nearby orchard with only minor abrasions.
The SZD 48 Jantar Standard 2 continued its flight after the impact, and the pilot was able to land safely at LKDK airfield. The OK-2666 subsequently struck the ground in an inverted spin, causing extensive damage to the airframe, including the destruction of the tail surfaces and the cockpit floor.
The investigation
The ÚZPLN investigation examined GNSS flight recorder data from both aircraft to reconstruct the trajectories leading to the collision. The investigation focused on the relative positions of the two gliders, the visibility conditions, and the maneuvers performed by both pilots. The commission also reviewed the competition rules regarding flight separation and circling direction in shared thermals.
Findings
- Both pilots were properly licensed and the aircraft were airworthy.
- Meteorological conditions provided good visibility, which should have allowed for the detection of the other aircraft.
- The pilots were operating in a high-density area with many other gliders, which increased the complexity of maintaining safe separation.
- The pilots failed to recognize the converging flight paths and did not perform any evasive maneuvers.
- The impact caused the structural failure of the OK-2266 canopy, which led to the pilot's forced egress and the subsequent crash of the aircraft.