Dart 15 stalls and spins in low slow turn off ridge

The pilot of a Slingsby T.51 Dart 15 was fatally injured after the glider departed controlled flight at low height while ridge soaring at Sutton Bank; aircraft destroyed. As lift weakened the glider descended through progressively lower passes along the ridge. Earlier chances to land on the secondary long-run field were not taken; air-to-air photography in the latter passes likely drew attention from the shrinking margin. From just above the ridge and near stalling speed, the pilot turned left for separation, then reversed right toward the airfield. The inner right wing stalled first and the glider rolled into a spin from too low to recover.

1. Local ridge soaring flight: The pilot of a Dart 15 flew a local flight from Sutton Bank during a vintage-glider event; after aerotow release the glider stayed close to the airfield in a westerly ~20 km/h wind.
2. Limited hill-soaring and type time: The pilot had limited experience on the Dart 15 and in hill soaring; its notes warn that in a 30-degree turn at low speed, extra bottom rudder drops the inner wing into a spiral dive.
3. Ridge lift weakened; height bled off: Ridge lift weakened as the wind shifted subtly; the glider descended over successive traverses, from ~30-90 m above the ridge to under ~15 m on the final pass, nose-high and unusually slow.
4. Air-to-air photography in low passes: The pilot's camera was found switched on at impact; time-stamps showed 27 photographs taken in flight, several in the final passes when onlookers already worried about the glider's height.
5. Low slow reverse turn back to airfield: From just above the ridge at minimal speed, the pilot turned left away from the slope, then reversed right toward the site, apparently attempting a late return rather than landing below.
6. Right wing stalls; rapid roll right: As the right turn developed, the inner right wing stalled first; the glider rolled rapidly right, nose down, entering a spin or spiral dive unrecoverable from the height available.
7. Pilot fatally injured; glider destroyed: The glider struck birch trees on the slope ~15 m below the ridge, fuselage pitched nearly vertical; the unconscious pilot died 20 days later. No pre-impact failure was found.