Mid-air collision between Speed Astir II and Ka 6 over Piz Tschierva, Switzerland
On August 12, 1982, a mid-air collision occurred between a Grob Speed Astir II and an Alexander Schleicher Ka 6 CR above Piz Tschierva, Switzerland. The Speed Astir II, piloted by a German national, collided with the Ka 6 CR from behind at an altitude of 3,807 meters. The Speed Astir II lost a portion of its wing and crashed into the mountain, resulting in the pilot's fatality. The Ka 6 CR sustained minor damage but was able to return safely to the Samedan Airport. No injuries were reported for the Ka 6 CR pilot, and there was no damage to third parties.
- Winch launch and climb: The Speed Astir II D-2904 launched by winch from Samedan at 14:27 and proceeded to soar in the local alpine area.
- Crowded thermal area: Around Piz Tschierva there were about 15–20 gliders using the same lift, flying mixed turning directions and figure‑eight patterns at varying altitudes.
- High-speed arrival: Shortly before 16:02 the Speed Astir approached the Piz Tschierva lift area at relatively high speed from outside the main gaggle, descending toward the group of gliders.
- Target glider not seen: While entering the dense group of gliders, the Speed Astir pilot did not see the Ka 6 CR HB-836 ahead in his flight path.
- Rear-quarter impact: At 16:02 the Speed Astir, banked about 55–60° right and on a roughly 325° track, struck the Ka 6 CR from behind and left at 3,807 m, with high relative speed.
- Wing loss and spiral: The collision severed a 3.27 m outer section of the Speed Astir’s right wing, causing the glider to flip longitudinally over the Ka 6 and enter an uncontrollable spiral dive toward terrain.
- Crash - fatal: The Speed Astir impacted the west face of Piz Tschierva around 3,400 m and was destroyed, fatally injuring the pilot, while the Ka 6 CR remained controllable and later landed safely at Samedan.