DG-800 stalls on near-vertical winch climb after seat slips back

The pilot of a DG-800 was fatally injured when the glider stalled at ~40 m AGL during a winch launch at Mollis and fell vertically onto the airfield; aircraft destroyed. Lift-off was early and the transition to climb was abrupt and too steep; the climb angle steepened to near-vertical until the cable auto-released at the CG hook, the glider rolled right and impacted nose-first. The pilot — 369 h total, 52 h on type but no winch starts on type, one winch launch since a 15-month break — was probably restricted in forward stick travel after sliding back against a shortened seat back. An incoming foehn front may have aggravated the climb.

1. Winch launch on RWY 01: After a morning of routine winch operations at Mollis on runway 01, the DG-800 S was readied for a single-seat winch launch, with the pre-flight control check clean.
2. Low winch currency, first on type: The pilot had not flown a winch launch in the past 90 days and, after a lengthy break, had made only one prior winch launch, none on this glider type.
3. Seat back shortened by prior owner: A previous owner had modified the seat back for a taller pilot and remounted it about 26 cm aft of the factory position; the pilot did not use the air cushion specified to reposition it.
4. Pilot slides rearward under acceleration: During the winch's full-power acceleration the pilot likely slid rearward against the shortened seat back, losing pedal contact and forward stick travel, matching the steep early climb.
5. Climb steepens to near-vertical: The glider appeared to lose airspeed and hang ever more steeply on the cable, likened by witnesses to a kite losing the wind, reaching a near-vertical pitch before the stall.
6. Cable auto-releases at CG hook: At the near-vertical attitude the cable angle exceeded the CG-hook's release threshold of about 83 degrees, and the hook auto-released without pilot input, unstopped by the winch driver.
7. Glider rolls right, falls from ~40 m: At about 40 m AGL the glider rolled over the right wing and dropped vertically toward the airfield, striking nose-first with no recovery attempted.
8. Pilot fatally injured; glider destroyed: The pilot was fatally injured and the glider destroyed; the loss of control stemmed from a seating-position shift that restricted control inputs during the winch launch.