What happened
On June 2, 1977, a pilot departed from Schänis airfield in a Cirrus glider, registration HB-941, for a training flight. During the flight, the aircraft entered a right-hand spin in the vicinity of the Mattstock. While the pilot made one radio contact during the afternoon to inquire about weather conditions near the Churfirsten, the aircraft failed to return to Schänis as scheduled. Following the absence of the aircraft and no report of an external landing, a search operation was launched.
The wreckage of the HB-941 was discovered the following morning by a military helicopter crew on the northwest side of the Mürtschenstock at an altitude of approximately 2,100 meters. The impact occurred in a steep, snow-covered area. The pilot sustained one fatality.
The investigation
Investigators examined the wreckage and found the aircraft had struck a 45-degree snow slope while in a right-hand spin. The impact was severe, with the nose of the fuselage penetrating through the snow to the rocky ground. The investigation confirmed that the aircraft's weight and center of gravity were within permissible limits and that the water ballast tanks were empty. No pre-existing technical defects were found in the airframe, controls, or instruments.
Medical examinations revealed that the pilot survived the initial impact for a period of time, but likely succumbed to hypothermia several hours later. The investigation also noted that the pilot had recently undergone retraining on a different glider type and had experienced a minor foot injury a few days prior to the accident.
Findings
- The aircraft entered a right-hand spin, which the pilot was unable to recover from, likely due to low altitude or delayed recovery attempts.
- The accident occurred in an area experiencing moderate turbulent thermals, which can facilitate dropping below the minimum flying speed.
- The pilot's recent training history indicated a tendency to react with delay during certain flight maneuvers.