Pilatus B4 stalls on a winch launch with a tail-heavy trim setting

The pilot was killed and the glider destroyed when it stalled on a winch launch at about 30 m and hit the grass nose-first. He had made only two winch launches on the type, the last two years earlier. The glider went into an unusually steep climb as it left the ground, dropped the left wing at the stall and rolled about 180 deg; the pilot released the cable and the winch driver cut it, too low to recover. The trim was found at notch 7 of 10 where the manual specifies 5, leaving the glider tail-heavy; the cable carried a 750 kp weak link instead of 500 kp, so it did not break.

1. First flight of the year: The glider had not flown in 2018 and the pilot prepared it for its first flight of the year. It was his third winch launch of the season, and he had made only two on the type.
2. Trim and weak link both wrong: The elevator trim was latched at notch 7 of 10 where the flight manual specifies notch 5, leaving the glider tail-heavy. The cable carried a 750 kp weak link where 500 kp is prescribed.
3. Unusually steep climb: The winch driver accelerated the cable, the glider rolled and went immediately into an unusually steep climb.
4. Stall at about 30 m: At about 30 m above the ground the glider stalled, the climb speed too low and the angle of attack too high. The pilot released the cable at once and the winch driver cut it.
5. Left wing drop and 180 deg roll: The glider dropped over the left wing and rotated about 180 degrees about its longitudinal axis, nose towards the ground, with too little height left to recover.
6. Vertical nose-first impact: It struck the grass vertically and at high speed, nose first. The cockpit area was destroyed and the pilot was killed.