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 was flown in a low-height, deep overflight along the runway, progressively bleeding off its speed so that by the last quarter of the field it had insufficient energy to climb over the trees at the end.
5. Continued low pass: Despite the student declining control and expressing concern about obstacles, the instructor continued the low, relatively slow flight toward the airfield boundary, apparently intending a turnaround maneuver.
6. Tree strike and spin-in: Near the northeastern airfield boundary, the ASK 13, still low and slow, failed to gain enough height to clear the treeline, struck a tree with the left wingtip, and entered a left-turning spiral descent into the forest.
7. Crash - serious injury: The glider was destroyed after coming to rest in the upper part of tall forest trees, the instructor was seriously injured, and the student sustained minor injuries, with additional ground damage in the wooded area.