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

On April 30, 2012, 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: Rolladen-Schneider LS6-C 18 (SN 6382, 1999 build, 706 h total, last annual inspection 21.04.2012; loading and CG within limits). Pilot 54 yo, SPL since 1999 with winch + aerotow ratings, class 2 medical valid (glasses + spare required); total ~550 h / 474 launches, ~50 h mountain flying; 6 flights in the last 90 days (two as familiarisation flights on a K 13 at Unterwössen). Launch 10:20 local by aerotow; long XC via St. Johann in Tirol — Saalfelden — St. Johann i.T. — Zell am See — return to Unterwössen. Field elevation 533 m AMSL; RWY 06 in use (asphalt 580×10 m, grass 660×25 m, both 056°/236°).
2. Cross-country course at Unterwössen: The pilot had been at Unterwössen for several days to attend a cross-country flying course with his own LS6-C 18. He had been briefed on local conditions by an instructor two days prior to the accident.
3. SE wind freshening to gusts >40 km/h: Per the Kampenwand weather station (Bavarian avalanche service, 30.04.2012): from 16:00 the wind speed increased from a mean of ~12 km/h to ~33 km/h, with gusts over 40 km/h, sustained until the accident time.
4. RWY 06 in lee of Gscheuerwand: Per the operations control (Luftaufsicht): the wind on the day was from a southeasterly direction, placing RWY 06 in the lee of the Gscheuerwand. The launch director had earlier given another pilot radio advice 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 around 18:00 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 contacted a group of trees on the east-side slope of the airfield ~260 m before the RWY 06 threshold. The left wing was broken to a 1 m stub; the wing-tip extension was severed; the right wing leading edge was damaged from the tree contact.
8. Ground impact in airfield, destroyed: After the tree strike the glider impacted the grass surface within the airfield boundary, ~200 m before the asphalt RWY 06 threshold. The cockpit was destroyed to the seat back; the fuselage tube was broken. Aircraft destroyed; pilot fatally injured. BFU concluded the investigation as a facts-only summary report (per § 18 FlUUG), with no analysis or conclusions.