ASK 13 canopy opens during aerotow, forcing a hard landing that injures a student

A student pilot was seriously injured when an ASK 13's canopy opened during the aerotow and the forced landing was heavy at Königsdorf; the glider was lightly damaged. On the day's first flight, an instructional aerotow, the canopy sprang open with a bang on the crosswind leg at about 100 m. The instructor took over, released and turned back; the two failed to reclose it. After another low turn it landed on a meadow, touched down sideways and pitched onto its skid, slewing about 90° before stopping. The canopy had not been properly locked: its bolts engaged only 1-2 mm, so it could not be lifted yet was unlatched, and could open in flight.

1. Instructional aerotow, first flight: An ASK 13 aerotow-launched at Königsdorf on runway 28 for an instructional flight, the first of the day, with an instructor and a student aboard.
2. Canopy not properly locked: The canopy lock let its bolts engage only 1-2 mm on placement, so the canopy could not be lifted yet was not truly latched — a false-secure state a lift check would not reveal.
3. Canopy springs open at about 100 m: On the crosswind leg at about 100 m, the canopy sprang open with a loud bang.
4. Instructor takes over, turns back: The instructor took control, released the tow rope and turned back toward the field; the two tried to reclose the canopy but could not.
5. Low turn onto a meadow: After another low turn the glider was set down on a meadow just north of the field.
6. Touches down sideways, onto the skid: It landed crabbing and pitched onto its skid, slewing about 90 degrees before stopping after some 10 m; the front-seat student was seriously injured and the glider lightly damaged.