Mid-air collision between Libelle H301 and Kestrel H 401 near Bever, Switzerland

On July 24, 1980, a mid-air collision occurred between a Glasflügel Libelle H301 and a Glasflügel Kestrel H 401 near Bever, Switzerland. Both aircraft were conducting training flights after launching from Samedan airfield. The collision happened at approximately 3400 meters altitude, resulting in the Kestrel becoming uncontrollable and crashing, while the pilot parachuted to safety with minor injuries. The Libelle sustained damage to its left wing but managed to return and land safely at Samedan. The official report cites insufficient airspace observation by both pilots as the cause of the collision.

1. Winch launch cruise: After a winch launch from Samedan, the Libelle pilot spent over two hours soaring in the Crasta Mora–Corviglia–Corvatsch area before returning toward a cumulus south‑east of Crasta Mora.
2. Congested thermal area: Approaching a cumulus south‑east of Crasta Mora, the Libelle pilot observed five to six gliders circling in the thermal and chose to avoid adding to the congestion by moving to the Crasta Mora ridge instead.
3. Unfavorable visibility: Lighting and mutual sighting conditions were unfavorable, with possible sun glare from front‑left and the Kestrel approaching slightly from below, making visual acquisition more difficult.
4. Inadequate lookout: Both pilots maintained insufficient airspace observation as they maneuvered near the south‑east flank of Crasta Mora, failing to see each other despite converging flight paths.
5. Near head-on collision: At about 3400 m, the Kestrel, flying slightly lower and from the left, collided almost head‑on with the Libelle, its T‑tail striking and damaging the Libelle’s left wing.
6. Kestrel control loss: The impact tore off part of the Kestrel’s right horizontal stabilizer, causing loss of pitch control and a subsequent inverted spin toward the terrain.
7. Crash - minor injury: The Kestrel pilot bailed out and landed by parachute with injuries on the south slope of Crasta Mora while the destroyed glider crashed, whereas the damaged Libelle remained controllable and landed safely back at Samedan.