ASW 24 pull-up stall; right spiral dive impact at low altitude

The pilot of an ASW 24 was fatally injured in a steep nose-down impact near Dunstable after the glider stalled in a low-altitude pull-up and entered a right spiral dive; aircraft destroyed. On the second winch launch of the day to ~275 m AGL the pilot flew along the Dunstable Downs ridge, completed a continuous right turn and one orbit, then pulled up steeply and levelled off at ~90 m AGL. As airspeed decayed close to the 1g stall speed in a 10+ kt tailwind, the glider banked left and entered a right spiral dive. After ~270° of descent it struck a crop field. A red windsock indicated conditions for instructor or Silver-qualified pilots only.

1. 2nd winch launch, ridge soaring: At 13:42 UTC the pilot of an ASW 24 was on his second winch-launched flight from the Dunstable gliding site. He released at ~275 m AGL and flew along the Dunstable Downs ridge. Wind 130° at 14 kt gusting 24 kt — blustery from the south-east. Pilot held a BGA glider certificate with ~274 h total (~10 h on type, 17 h in last 90 days).
2. Red windsock flown at the site: A red windsock at the site indicated to pilots that conditions were such that only instructor pilots and those holding a Silver gliding qualification were recommended to fly. The pilot held neither rating, though he had recently flown a club trip to the Pyrenees in more challenging conditions.
3. Steep pull-up, level off ~90 m AGL: For reasons not determined — possibly to exploit lift — the pilot performed a steep pull-up. GPS data showed the glider's groundspeed reducing to 47 kt at the top of the pull-up, at which point it levelled off at about 90 m AGL and banked to the left.
4. Tailwind component ~10+ kt: The wind direction at the level-off would have produced a tailwind component of around 10 kt, possibly more in gust. Combined with the low groundspeed at the top of the pull-up, this placed the indicated airspeed close to or below the 1g stall speed (~37 kt at the aircraft's accident weight).
5. Stall and right spiral dive: Whether the left bank was the pilot's intention or the result of a wing drop was not determined. Witnesses described the glider stalling and entering a spiral dive to the right; the wreckage examination confirmed a right spiral dive on impact. Recovery requires lowering the nose, levelling the wings, then pulling out — insufficient height was available.
6. Steep nose-down impact in crop field: After turning through approximately 270° the glider struck a crop field near Dunstable in a steep nose-down attitude. The aircraft was destroyed and the pilot was fatally injured. Wreckage examination showed no pre-impact failure; landing gear retracted, airbrakes closed.