Fallo estructural del DFS Kranich II durante acrobacias en Bellechasse resulta en fatalidad
El 6 de junio de 1965, un DFS Kranich II experimentó un fallo estructural durante un vuelo de entrenamiento acrobático en Bellechasse, Suiza. El instructor de vuelo y un alumno piloto realizaban una maniobra de looping cuando el ala derecha se desprendió, provocando el accidente de la aeronave. El alumno piloto logró saltar en paracaídas a salvo, pero el instructor no pudo escapar y murió en el impacto. La investigación reveló que el planeador estaba sobrecargado para maniobras acrobáticas, lo que contribuyó al fallo estructural.
- Aerotow training flight: The instructor and student launched by aerotow from Bellechasse for a third dual aerobatic training flight in the DFS Kranich.
- Glider overloaded: For this flight the Kranich was about 45 kg above the maximum permitted weight for aerobatics, with the centre of gravity 24 mm ahead of the forward limit.
- No g-meter installed: The glider was not equipped with a required accelerometer, so the instructor had no direct indication of g-loads during aerobatic maneuvers.
- Looping pull-out: From about 620 m AGL the instructor demonstrated a looping, and at roughly 500 m AGL during the pull-out he applied a strong nose-up input that generated a peak structural load.
- Right wing failure: At about 30° nose-up attitude the right wing failed at the main attachment, rotated upward, and separated, leaving the glider uncontrollable.
- Student parachute escape: The student pilot exited his seat without difficulty and successfully descended under his parachute, while the rear canopy opened but the instructor did not or could not exit.
- Crash - fatal: The crippled glider crashed into a nearby field, destroying the aircraft and fatally injuring the instructor while the student remained unhurt.