ASW 28-18 stalls in foehn-turbulent slope climb

The pilot of an ASW 28-18 was fatally injured when the glider stalled climbing toward a mountain slope in turbulent foehn near Falknis; aircraft destroyed. After aerotow from Schänis and a cross-country via the Churfirsten and Sargans, the pilot cruised toward the Falknis ridge at ~2,400 m in strengthening late-afternoon foehn. He chose an ascending track directly toward the slope to use slope lift. Over the last 40 s of recorded flight, airspeed decayed to ~75 km/h close to terrain; the glider stalled and the pilot couldn't correct the nose-high attitude before impact at ~2,170 m. He had low recent solo time on type after a long break.

1. Aerotow + XC to Falknis ridge: The pilot took an aerotow from Schänis and flew a cross-country leg via the Churfirsten and the Sargans area, then cruised toward the Falknis ridge at about 2,400 m AGL.
2. Strengthening foehn turbulence: During the late afternoon the foehn flow strengthened, with strong southerly winds aloft and gusty, turbulent conditions in the Sarganserland and at Falknis.
3. Low recent solo after long break: The pilot had relatively low overall gliding hours on the type and very little recent solo time after a long interruption, reducing his familiarity with the type's energy management near terrain.
4. Climbing track toward slope to use lift: Approaching Falknis, the pilot chose an ascending track directly toward the mountain flank in order to use slope lift, rather than approaching along the ridge with energy margin.
5. Airspeed decays to ~75 km/h: Over the last ~40 seconds of recorded flight, the indicated airspeed progressively decreased to about 75 km/h close to the terrain — leaving no margin in the gusty foehn flow.
6. Stall, no correction before impact: The low-airspeed, nose-high attitude in turbulent foehn produced an aerodynamic stall; the pilot was unable to correct the pitched-up attitude before reaching the slope.
7. Slope impact at ~2,170 m; pilot fatal: The ASW 28-18 struck a steep grass and rock-covered slope near the west end of the Falknistürme at about 2,170 m and was destroyed. The pilot was fatally injured.