DFS Kranich II training incident during approach in Löhningen, Switzerland
On December 5, 1959, a DFS Kranich II experienced a stall and spin during a training flight in Löhningen, Switzerland. The incident occurred when the student pilot exceeded the aircraft's critical angle of attack while executing a full circle to lose altitude before landing. The glider entered a spin from approximately 80 meters above ground, resulting in a crash. The flight instructor sustained minor injuries, while the student pilot was severely injured. The aircraft was destroyed, and discrepancies in the airspeed indicators were noted but not confirmed as causal.
- Training circuit flight: During a winch-launch training flight, the instructor and student flew a second circuit in the Kranich II with the student flying and the instructor supervising.
- Student flies too slowly: On both the first and second flights the student repeatedly tended to fly below the instructed normal approach speed of about 70 km/h, only briefly correcting when prompted by the instructor.
- Low height for maneuvering: On the second circuit the glider remained too high for landing, leading the instructor to have the student fly additional 360° turns at relatively low altitude to lose excess height.
- Overshoot of stall in turn: While completing the second left 360° turn at about 80 m above ground, the student increased bank and applied strong right rudder, causing the aircraft to exceed its critical angle of attack in the low-speed turn.
- Late instructor intervention: The instructor reported attempting to take over the controls as the bank and rudder input became excessive, but his intervention came too late to prevent the stall and spin entry.
- Stall and spin at 80 m: The glider abruptly stalled from the left turn, dropped into a left spin from about 80 m above ground, and completed nearly two turns with no altitude available for recovery.
- Crash - serious injury: The glider impacted the soft ground steeply and was destroyed, the instructor received minor injuries, and the student sustained serious injuries.