Ka 6 BR aborts aerotow at 5 m on tail noise, ground-loops in rapeseed

A Ka 6 BR was substantially damaged on an aborted aerotow at Grenchen (Switzerland); the pilot was uninjured. He held 41 hours total and 46 minutes on type, all flown in the prior 90 days. After a normal liftoff on aerotow he heard an unfamiliar noise from the tail and released the rope at about 5 m. The remaining runway was insufficient, so the pilot put the glider down in a rapeseed field beyond the runway end. The glider ground-looped (Ringelpietz), damaging the rear fuselage, elevator and rudder. The pilot suspected the noise came from the tail wheel still spinning after liftoff; the abrupt low release was the decisive driver.

1. Aerotow start ~15:00 LT: At about 15:00 LT on 24 April 2015 the pilot launched a Ka 6 BR on aerotow from Flugplatz Grenchen (LSZG). The ground roll and initial climb were normal.
2. 46 min on type, 41 h total: The pilot held a glider licence with about 41 hours total experience and 1:40 hours in the prior 90 days. He had only 46 minutes on the Ka 6 BR — all of his time on type was flown in the prior 90 days as a recent introduction to the type.
3. Unfamiliar noise from tail: Shortly after liftoff the pilot heard a noise from the tail area of the glider that was unfamiliar to him.
4. Release at ~5 m: Interpreting the noise as a possible problem, the pilot decided to abort the takeoff and released the tow rope. He estimated the glider's height at about 5 m above the ground at the moment of release.
5. Runway too short for landing: After release the pilot realised that the remaining runway length was not enough for a landing on the runway.
6. Outlanding in rapeseed field: The pilot landed the glider in a rapeseed field located beyond the runway end.
7. Ground loop; tail damaged: During the rollout in the field the glider ground-looped (Ringelpietz). The rear fuselage, the elevator and the rudder were damaged. The pilot was uninjured. He later suggested that the noise he had heard had come from the tail wheel, which was still spinning freely after liftoff.