Collision du Ka 8 B avec des obstacles près de l'aérodrome de Birrfeld lors d'un vol d'entraînement

Le 15 mai 1980, un planeur K 8 B a décollé de l'aérodrome de Birrfeld pour un vol d'entraînement local. Le pilote a rencontré des courants descendants et des turbulences près du Chestenberg, entraînant une perte rapide d'altitude. En tentant d'éviter les lignes électriques, l'aile gauche a heurté un arbre, provoquant le détachement de l'aile et le crash du planeur. Le pilote a subi de graves blessures et l'appareil a été fortement endommagé. Le rapport officiel a cité une altitude insuffisante et la proximité de la colline comme facteurs contributifs.

1. 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.
2. Entered lee downdraft: On the south side of the Chestenberg, the glider entered the lee of the slope and rapidly lost altitude.
3. 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.
4. Limited experience: The pilot had relatively low total experience and the investigation cited insufficient airmanship and poor flight tactics as contributing factors.
5. 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.
6. 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.
7. 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.