LS4 pilot joins a thermal between two circling gliders and collides with an LS8

An LS4-A and an LS8-18 collided in a thermal near Staré Sedlo on a junior world championship task as the LS4 pilot turned in to join between two gliders circling at nearly his level; the LS4 pilot bailed out and both were unhurt. The LS8 pilot, circling right behind a team-mate at about 1,830 m MSL, saw the LS4 some 50 m below and outside, then lost it behind his bank and held a steady turn to stay predictable. The tracks converged at 40°; five seconds after the FLARM alarm the LS8's wing struck the LS4's canopy from above and behind. The LS4 fell into a forest, substantially damaged; the LS8 landed in a field 7 km away, lightly damaged.

1. Thermaling on a championship task: On day 9 of a junior world championship flown from Tábor, the pilot of an LS8-18 circled right behind a team-mate at about 1,830 m MSL in a thermal shared by several gliders.
2. Several gliders in one thermal: Other competitors were passing through or circling nearby; the report noted that the pilots' attention was divided among them on top of flying and navigating.
3. LS4 turns in to join at same level: After six minutes of straight glide the LS4-A pilot chose the thermal ahead and began a gentle right turn to slot between two gliders he saw circling to his right at nearly his level.
4. Seen, then lost behind the bank: The LS8 pilot saw the LS4 about 50 m below and outside his circle, then lost it as he banked; he held bank and speed constant to remain predictable. The tracks converged at about 40°.
5. FLARM alert five seconds out: Both FLARM units were working; the alarm came about half a turn after the LS4 was last seen, some five seconds before impact, too late to act, probably because of the other gliders around.
6. Wing strikes the canopy from behind: The LS8's left wing hit the top of the LS4's canopy from above and behind and shattered it; the LS4 pitched into a steep descent.
7. LS4 pilot bails out: Unsure how badly his glider was damaged and with the speed building, the LS4 pilot left it at about 1,220 m AGL and landed by parachute 1.7 km from the wreck, unhurt.
8. Field landing and a wreck in a forest: The LS8 pilot checked his controls, had his team-mate look the glider over and landed in a harvested field 7 km away; the LS4 fell inverted into a forested ravine.