Two ASW 19s on crossing orbits collide in shared thermal
Two newly-licensed pilots collided in a shared right thermal at ~3,100 m; the lower ASW 19, climbing at ~3 m/s, struck the upper at its ceiling with its left wingtip. Both bailed out and parachuted safely; both gliders destroyed in a rocky basin. At an informal Bex club soaring day they met over the Pic Chaussy-La Para ridge; the lower saw the upper enter a right spiral 150 m above and joined. Visual contact was lost; one radio call placed the upper at 3,100 m, then nothing. Their right orbits crossed; ~1 s warning before impact. Cause: insufficient mutual surveillance; the upper pilot should widen or exit to keep others below visible.
- Informal Bex soaring day; ridge thermal: Two ASW 19s (HB-3172, HB-1573) flew an informal soaring day at Bex. Both met around 16:15 over the Pic Chaussy-La Para ridge in clear weather with strong turbulence.
- Lower joins upper in right thermal: At about 2,700 m, the lower pilot spotted the upper aircraft ~150 m above, arriving from the west and spiralling right. He turned right to join the same thermal.
- Visual contact lost; single radio call: The lower pilot lost sight of the upper aircraft and radioed its position; the upper pilot answered from 3,100 m near Lac Lioson. No further contact followed.
- Right orbits crossed near upper ceiling: The two right-turning orbits crossed near the upper aircraft's ceiling, with a limited rear-left view. Each pilot spotted the other about a second before impact, too late to react.
- Left wingtip strike; both bail out: HB-1573 (lower) struck HB-3172 (upper) with its outer left wing. Both pilots parachuted to safety uninjured; both gliders were destroyed. Cause: insufficient mutual surveillance.