Ka 6 crash in Kienberg after attempted landing in challenging conditions
On May 5, 1976, an Alexander Schleicher Ka 6 CR experienced an accident near Kienberg, Switzerland. The pilot, who took off from Birrfeld Airfield, encountered weak thermal conditions and was forced to search for a suitable landing site. After attempting to gain altitude near Kienberg, the glider stalled and collided with a tree and a telephone pole before crashing onto a village street. The pilot sustained serious injuries, and the glider was destroyed. The official report cites pilot decision errors and failure to maintain minimum flight speed as probable causes.
- Aerotow cross-country: The pilot aerotowed from Birrfeld to 1000 m above the airfield to begin a planned 300 km cross-country flight.
- Weak thermals en route: After release the pilot encountered generally weak and only locally moderate thermals over the Aaretal and toward the Jura, resulting in a mostly continuous descent.
- Low altitude near Kienberg: Despite poor climb conditions the pilot continued toward the Jura with inadequate height reserve and arrived near Kienberg at low altitude, already searching for a landing field.
- Late landing decision: The pilot delayed committing to the selected outlanding field and, at less than about 50 m above ground over the village, chose to turn away to exploit a perceived weak climb instead of flying a direct landing pattern.
- Tight low-altitude turn: Over Kienberg the pilot initiated a flat right turn, then tightened the turn to try to realign with the intended landing direction while still very low.
- Stall and loss of control: During the tightened turn at low height the glider dropped below minimum speed, stalled over the right wing, and the pilot lost control.
- Crash - serious injury: The glider struck a tree and a telephone pole and then crashed onto the village street, seriously injuring the pilot and destroying the aircraft.