Puchacz training: third spin not recovered from ~460 m AGL

The instructor and student of a Puchacz were fatally injured in an unrecovered training spin near Husbands Bosworth; aircraft destroyed. After aerotow release at ~915 m AGL the crew performed two left-hand spins with normal recoveries. A third spin entered at ~460 m AGL continued for about five turns; the glider was last seen in a steep left turn below 30 m before the left wing struck. No pre-impact failure was found and no cause could be established. The student had only practised spinning in a more benign K13; the instructor's recent currency on Puchacz was very limited.

1. Aerotow training flight to ~915 m AGL: A two-seat Puchacz trainer was aerotow-launched from Husbands Bosworth on a training flight with an instructor and student, releasing normally at ~915 m AGL for probable spinning practice.
2. Two spins to left with normal recoveries: Witnesses saw the glider spin left from a nose-high attitude, recover after 1-1.5 turns, regain height, then spin left again with a normal recovery, climbing away under control.
3. Limited Puchacz currency on both seats: The student's prior spin training had been on a more benign type, and he had not yet spun a Puchacz. The instructor's recent currency on the Puchacz was also very limited.
4. Third spin entered at ~460 m AGL: Witnesses on the ground saw the nose pitch up steeply before the glider entered a third left spin at an estimated 460 m AGL, well below the two previous recovered spins.
5. About five turns; no recovery observed: Ground witnesses watched about five turns of a steep, nose-down left spin with no apparent recovery action; the rotation may have increased slightly before it disappeared behind a ridge.
6. Left wing strike below 30 m; both fatal: A second pilot saw the glider clear a hedge in a left turn below 30 m before the left wing, then the nose, struck the ground at about 60° pitch-down; both occupants were fatally injured.