Pilatus B4-PC 11AF stalls during landing attempt at Fricktal Schupfart airfield
On August 16, 1973, a Pilatus B4-PC 11AF experienced a stall while attempting to land at Fricktal Schupfart airfield in Switzerland. The pilot, who was conducting a local training flight, released from the tow at approximately 50-70 meters altitude after realizing the glider was higher than the tow plane. During the subsequent landing approach, the glider flew too high and the pilot attempted a turn to re-approach the runway. The glider stalled during this low-altitude turn and impacted the ground with its left wing. The pilot was uninjured, but the glider sustained significant damage.
- Aerotow initial climb: The glider HB-1119 departed Fricktal-Schupfart on aerotow from runway 26 for a local training flight and climbed normally to about 50–70 m above the field.
- Excess tow height: At approximately 50–70 m altitude the pilot found himself flying significantly higher than the towplane and lost proper tow position control.
- Early tow release: Because he was too high above the tug, the pilot released from tow at low altitude and turned left to return for an opposite-direction landing on runway 08.
- High, no airbrakes: On the return approach the pilot overflew the airfield at about 5–8 m without deploying airbrakes, resulting in an approach that was too high.
- Low-altitude re-approach: After overflying the runway, the pilot pulled up slightly at the end of runway 08, offset slightly right, and initiated a low-altitude left turn to set up a new landing approach.
- Stall in turn: During this low-altitude reversal turn the bank angle increased, the glider’s speed dropped below minimum, and it stalled and slipped inward, striking the ground with the left wing.
- Crash - no injury: The glider impacted with its left wing while the fuselage and right wing lodged in a tree, causing serious aircraft damage but no injury to the pilot.