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 (LSMF) on RWY 01 with northeasterly light winds, the DG-800 S was readied for a single-seat winch launch. A pre-flight control check had been completed without findings.
2. Low winch currency, first on type: The pilot held about 369 h total and 52 h on type, but had not flown in the last 90 days on the accident type. After a ~15-month training break he had completed one winch launch (on a DG-300) the prior month. This was his first ever winch launch on a DG-800.
3. Seat back shortened by prior owner: The seat back had been modified by a previous owner for a 186 cm body and re-mounted ~26 cm aft of the factory forward position. The accident pilot was 172 cm tall and did not carry the air cushion specified in the flight manual to reposition the back rest.
4. Pilot slides rearward under acceleration: During the full-power winch acceleration the pilot probably slid rearward against the shortened back rest, losing pedal contact and forward stick travel. This is consistent with the early lift-off and the abrupt, over-steep transition to the climb.
5. Climb steepens to near-vertical: The glider appeared to lose airspeed and hang ever more steeply on the cable. Witnesses likened it to a kite that has lost the wind; the pitch attitude reached near-vertical before the stall.
6. Cable auto-releases at CG hook: At the near-vertical attitude the cable angle exceeded the CG-hook geometric release threshold (~83°) and the hook auto-released. A pilot-initiated release in this attitude would have worsened the situation; analysis judges a self-release as most likely. The winch driver did not interrupt the launch.
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: Rescue services were alerted immediately and reached the site within minutes; by then a gusty southerly foehn had broken through across the valley. The pilot, seriously injured at the scene, later died of his injuries in hospital. The glider was destroyed. The probable cause was loss of control on the winch launch attributable to a seating-position shift that restricted control inputs; insufficient recent winch training, no prior winch experience on type, and limited mental preparation for winch-launch risks contributed, with a possible wind-shear contribution from the arriving foehn.