Ka 8 B collision with obstacles near Birrfeld airfield during training flight
On May 15, 1980, a K 8 B glider took off from Birrfeld airfield for a local training flight. The pilot encountered downdrafts and turbulence near the Chestenberg, leading to a rapid loss of altitude. While attempting to avoid power lines, the left wing struck a tree, causing the wing to detach and the glider to crash. The pilot sustained serious injuries, and the aircraft was heavily damaged. The official report cited insufficient altitude and proximity to the hillside as contributing factors.
- Ridge flight return: After a local training flight, the pilot was returning by ridge flying from the Aarau area toward Birrfeld in the late afternoon.
- Entered lee downdraft: On the south side of the Chestenberg, the glider entered the lee of the slope and rapidly lost altitude.
- Low altitude near field: Approaching Brunegg, the glider was only about 550 m MSL, roughly 150 m above the nearby Birrfeld airfield, leaving little height margin for further soaring attempts.
- Limited experience: The pilot had relatively low total experience and the investigation cited insufficient airmanship and poor flight tactics as contributing factors.
- Continued ridge search: Instead of committing to an immediate landing or outlanding, the pilot turned left to follow the north side of the Chestenberg toward WNW in search of lift at very low height.
- Turbulence and avoidance turn: Contrary to expectations the glider encountered strong turbulence and sink, and while attempting to avoid a high-voltage power line the pilot turned left toward the slope at very low altitude.
- Crash - serious injury: The left wing struck the top of a tree, was torn off, and the glider crashed near Birrfeld, seriously injuring the pilot and heavily damaging the aircraft.