ASK 13 forest crash — instructor's simulated launch failure too low and slow

During a training flight at Ohlstadt-Poemetsried, the instructor of an ASK 13 was seriously injured and the student lightly injured in a crash into forest. The instructor flew a simulated winch-launch interruption from a low overflight, letting airspeed bleed off along the runway below the margin needed for a climb-out or a 180 deg turn-back. By the airfield end the glider had no energy left to clear the trees or initiate the turn; the left wing struck a tree and the glider spiraled into the woods. The exercise was set up too low and too slow for the configuration and the available terrain.

1. Training circuit flight: During a winch-launch training flight in the circuit, the ASK 13 with instructor and low-time student was flying in the downwind leg after release.
2. Simulated launch failure: Shortly before turning base, the instructor announced and initiated a simulated winch launch interruption exercise, planning a low-altitude turnaround/return.
3. Exercise too advanced: The simulated start interruption with turnaround was introduced at a very early stage of the student’s training and not in accordance with the recommended DAeC training methodology.
4. Low height and energy: The glider flew a low, deep pass along the runway, progressively losing speed until it lacked enough energy to clear the trees at the far end.
5. Continued low pass: Despite the student declining control and voicing concern about obstacles, the instructor continued the low, slow flight toward the airfield boundary, apparently intending a turnaround.
6. Tree strike and spin-in: Near the northeastern boundary, the ASK 13, still low and slow, failed to clear the treeline, struck a tree with its left wingtip, and entered a left spiral descent into the forest.
7. Crash - serious injury: The glider was destroyed after coming to rest in the tops of tall forest trees; the instructor was seriously injured and the student sustained minor injuries.