LS6-C tightens base-to-final turn in lee-side gusts, wing hits trees

The 54-year-old pilot of an LS6-C 18 was fatally injured at Unterwössen; the aircraft was destroyed. The 54-year-old pilot, on a cross-country course, had aerotowed at 10:20 via St. Johann in Tirol, Saalfelden and Zell am See. By late afternoon the SE wind had freshened to gusts >40 km/h, placing RWY 06 in the lee of the Gscheuerwand; pilot advised by radio to delay landing. ~18:00 the glider turned base-to-final with progressively steeper bank, overshot the centerline, right wing struck trees on the east slope ~260 m before the threshold, impacted the grass within the airfield. Pilot fatally injured.

1. Landing approach at Unterwössen: The pilot flew the LS6-C 18 on a long cross-country flight via St. Johann in Tirol, Saalfelden, and Zell am See, returning to land at Unterwössen, a mountain airfield with RWY 06 in use.
2. Cross-country course at Unterwössen: The pilot had been at Unterwössen for several days attending a cross-country flying course with his own glider, briefed on local conditions by an instructor two days before the accident.
3. SE wind freshening to gusts >40 km/h: From mid-afternoon, wind speed increased from a mean of about 12 km/h to 33 km/h, with gusts over 40 km/h, sustained until the time of the accident.
4. RWY 06 in lee of Gscheuerwand: Wind that day was from the southeast, placing RWY 06 in the lee of the Gscheuerwand; the launch director had earlier warned another pilot about turbulence in the approach sector.
5. Continued approach despite delay advice: Per witnesses: as the wind freshened in the late afternoon, the pilot was advised by radio to delay landing until conditions improved. The pilot continued the approach to RWY 06.
6. Overshoot + tightening base-final turn: Witnesses observed the glider on base over the Ache river turning final for RWY 06; the bank angle increased through the turn and the glider overshot the extended centerline of RWY 06.
7. Right wing hits trees on east slope: During the tightening turn, the right wing struck trees on the east slope about 260 m before the RWY 06 threshold; the left wing broke to a 1 m stub.
8. Ground impact in airfield, destroyed: After the tree strike the glider hit the grass within the airfield boundary about 200 m before the RWY 06 threshold; the cockpit was destroyed. The pilot was fatally injured.