What happened
On July 4, 2010, at 15:02 UTC, a mid-air collision occurred approximately 10 km southwest of Ružomberok, Slovakia, during the 31st FAI World Gliding Championships. The accident involved two gliders, a Discus 2a (registration OK-7000) and a Discus 2T (registration SE-UOA), both participating in competitive flight tasks.
The pilot of the Discus 2a was circling in a right-hand turn within a thermal along with other aircraft to reach the necessary altitude for the competition task. Simultaneously, the pilot of the SE-UOA was maneuvering to join this same thermal. While attempting to integrate into the existing circle of gliders, the pilot of the SE-UOA entered the flight path of the established group and failed to maintain safe separation. The pilot of the SE-UOA observed the OK-7000 approaching from below and behind during a right-hand turn; despite an immediate attempt to avoid the collision by pulling on the control stick, the two aircraft collided at an altitude of 2,230 meters.
Following the impact, both pilots checked their aircraft's flight controls and decided to terminate their competition tasks. The OK-7000 landed at Ružomberok airport, while the SE-UOA landed at Prievidza airport. Both pilots were uninjured.
The investigation
The investigation examined the flight paths of both aircraft, the meteorological conditions, and the pilot qualifications. The weather at the time was stable with excellent visibility and no significant meteorological phenomena that could have contributed to the accident. Both pilots were found to be fully qualified for their respective aircraft types and possessed sufficient flight experience for competition flying. Neither pilot was under the influence of alcohol or drugs.
The investigation also reviewed the equipment on board. The OK-7000 was equipped with a FLARM collision warning system, an ELT, and GNSS flight recorders. The SE-UOA was equipped only with a GNSS flight recorder. The structural damage to the aircraft was documented, noting that the OK-7000 suffered a broken cockpit canopy and the loss of its right wing approximately two meters from the tip, while the SE-UOA sustained various skin tears and delamination across its fuselage and tail surfaces.
Findings
- The pilot of the SE-UOA, while attempting to join the thermal, disrupted the established flight path of the aircraft already circling in the updraft.
- The pilot of the SE-UOA failed to maintain safe separation distances from other aircraft.
- Despite an evasive maneuver attempt by the pilot of the SE-UOA, a collision occurred.