Pilatus B4 crash at Schafberg results in fatality during training flight
On August 15, 1981, a Pilatus B4-PC 11AF crashed on the slopes of Schafberg near Blinnenhorn, Switzerland. The pilot departed from Münster airfield for a training flight and lost control of the aircraft, resulting in a fatal crash at approximately 1855 local time. The glider was destroyed upon impact, and the pilot, who had limited mountain flying experience, was killed. The investigation found no pre-existing technical faults with the aircraft, and weather conditions were reported as fair with weak thermals.
- Aerotow training flight: The pilot departed Münster/VS at 1515 local on an aerotow in Pilatus B4 HB-1566 for a solo mountain training flight and released the tow after about ten minutes.
- Limited mountain experience: The pilot had low overall glider time and only a brief prior mountain-flying introduction and one earlier solo mountain flight in the accident type.
- Weak, irregular thermals: In the accident area around the time of the crash, only weak, somewhat irregular thermals (“Nullschieber”) were present, allowing height to be maintained but not gained.
- Entry to spin/spiral: For unknown reasons, the glider entered an uncontrolled right-hand autorotation, observed as a right spin or steep spiral.
- Low-altitude rotation: The glider remained in the right-hand spin for about one to one and a half turns without recovery and descended toward the slope.
- Crash - fatal: The glider impacted the rocky west slope of the Schafberg at approximately 2560 m, was destroyed, and the pilot was fatally injured.