Standard Cirrus crash during return to base near Hildisrieden, Switzerland

On May 17, 1992, a Schempp-Hirth Standard Cirrus was involved in an accident near Hildisrieden, Switzerland. The pilot, on a training flight after a long hiatus, was towed to an altitude of 1050 meters but mistakenly believed he was at 1300 meters due to an incorrect altimeter setting. Encountering weak thermals and poor visibility, the pilot attempted to return to the airfield. During a turn at low altitude, the glider stalled and crashed, resulting in significant damage to the aircraft and serious injuries to the pilot.

1. Aerotow training flight: The pilot, with very little recent flight training, departed Luzern-Beromünster on an aerotow training flight after an interruption of almost one year.
2. Altimeter mis-set: The altimeter was incorrectly set to 1040 hPa instead of the actual 1024 hPa QNH, causing it to overread by about 150 m and giving the pilot an overly optimistic impression of his height.
3. Low altitude near field: After releasing at an actual height of about 1050 m and losing height in weak thermals and poor 4 km visibility with a gusty NE wind, the pilot approached the airfield area and found himself at only about 100 m above ground unable to reach the runway directly.
4. Turn downwind at low height: Over a small wood near the hamlet of Schopfen, at about 100 m above ground, the pilot initiated a 180° reversal turn into downwind in an attempt to reposition despite the low height and gusty conditions.
5. Stall in reversal turn: During this low-altitude reversal turn the glider’s airspeed dropped below minimum flying speed, leading to a stall and loss of control.
6. Crash - serious injury: The glider impacted nose-first at the edge of a field, bounced and rotated 180° before striking tail-first in a meadow, destroying the aircraft and seriously injuring the pilot.