Nose-heavy trim on ASK 23 winch launch — hard impact
The pilot of an Alexander Schleicher ASK 23 was seriously injured in a winch-launch accident at Unterwössen (Germany) and the aircraft was substantially damaged. By the pilot's statement the trim had been set nose-heavy, although the manual specified tail-heavy for winch launch. After a flat climb the pilot found the winch pull insufficient and released the cable at about 10 m. The stick was pushed forward, the glider felt sluggish, and he pushed harder. It descended at 30 to 40 degrees and impacted from about 7 m, bounced and impacted again. Nose-heavy trim and strong forward stick on a low release drove the steep nose-down attitude.
- Winch launch climb: During a winch launch from RWY 06 at Unterwössen, the ASK 23 accelerated and lifted off into an initially normal but persistently shallow climb.
- Cable release low: As the shallow climb continued and cable slack developed, the pilot, feeling the winch pull was insufficient, released the cable at about 7–10 m above ground.
- Non‑optimal trim: Contrary to the flight manual recommendation for mid to slightly tail-heavy trim in winch launch, the pilot had set the trim to nose-heavy, increasing forward pitching tendency after cable release.
- Strong nose‑down input: After cable release the pilot initially perceived the glider as unresponsive, then pushed more strongly forward, driving the nose down toward the ground at a steep angle.
- Repeated hard impacts: The glider struck the ground heavily from about 7 m, briefly became airborne again, then impacted a second time with additional rotation, while radio calls from the launch director went unheeded.
- Crash - serious injury: The glider came to rest badly damaged along a 70 m ground scar within the winch launch area, and the pilot sustained serious injuries.