Collision en vol de deux planeurs K8B près de l'aérodrome de Schupfart entraîne un décès

Le 25 juin 1972, deux planeurs Alexander Schleicher K 8 B sont entrés en collision en vol à environ 2,5 km au sud-sud-ouest de l'aérodrome de Schupfart en Suisse. La collision s'est produite lorsque le pilote d'un planeur a percuté l'autre par derrière. Le pilote du premier planeur a pu se sauver en parachute, tandis que l'autre pilote a été mortellement blessé lorsque son appareil s'est écrasé. L'incident a entraîné la destruction d'un planeur et des dommages importants à l'autre. Les conditions météorologiques étaient claires et aucun dysfonctionnement technique n'a été signalé sur les appareils.

1. Thermaling in gaggle: Both K8B gliders HB-906 and HB-738 were thermaling in right-hand circles at similar altitude, laterally offset within the same general lift area near Schupfart.
2. HB-906 turns toward HB-738: The pilot of HB-906 leveled out of his right-hand turn, left his own lift area, and flew directly toward HB-738 from behind and to its left at approximately the same altitude.
3. Inadequate lookout: Investigators considered that the HB-906 pilot may not have seen HB-738, possibly due to sun glare, a blind spot, or insufficient airspace scanning while maneuvering in the thermal.
4. HB-738 evasive turn: Seeing HB-906 flying toward him on a collision course, the HB-738 pilot tightened his right-hand turn as steeply as possible in an attempt to avoid impact.
5. Mid-air collision: HB-906’s canopy area struck the left aileron of HB-738, and subsequent contact between HB-906’s right wing and HB-738’s tailplane caused severe structural damage to both gliders.
6. Bailout from HB-738: After HB-738 entered a flat spin, its pilot opened the canopy, released his harness, and successfully bailed out under parachute, while HB-906’s pilot jettisoned the canopy and opened his belts but did not or could not complete a parachute escape.
7. Crash - fatal: HB-906 entered a descending inverted spiral and crashed into a steep wooded slope fatally injuring its pilot, while HB-738, though heavily damaged, was left without pilot on board after the successful bailout.