Grob G-103A Twin II Acro Absturz beim Hangflug in der Nähe von Claro, Schweiz
Am 10. April 1999 war ein Grob G-103A Twin II Acro in einen Unfall in der Nähe von Claro, Schweiz, verwickelt. Das Segelflugzeug, gesteuert von einem Schweizer Staatsbürger, verlor während eines Hangflugs die Kontrolle und stürzte in ein bewaldetes Gebiet. Der Pilot erlitt leichte Verletzungen, während der Passagier schwer verletzt wurde. Das Flugzeug wurde vollständig zerstört. Der offizielle Bericht identifizierte die Ursache als Kontrollverlust aufgrund unzureichender Gebirgsflugtaktiken.
- Ridge soaring flight: After aerotow departure from Magadino and several hours of cross‑country soaring, the pilot was ridge and thermal soaring along the Parusciana area north of Castione at about 1100 m MSL.
- Low height near slope: While following the ridge toward Pizzo di Molinera, the glider was flown at an estimated 100 m above ground and 50–100 m laterally from the slope, leaving little margin for recovery.
- Inadequate speed margin: The pilot flew at about 90 km/h in conditions with forecast wind shear and turbulence, without increasing speed above normal minima despite the low altitude and mountain environment.
- Encountered strong sink: During a wide left turn following the ridge, the glider transitioned from weak lift into a strong downdraft, abruptly reducing angle of attack and lift at an already low airspeed.
- Stall and loss of control: At low speed and low height, the glider stalled and the pilot lost control, with insufficient altitude available for recovery.
- Crash - serious injury: The stalled glider descended into the forested slope near Claro, destroying the aircraft, seriously injuring the front‑seat passenger and slightly injuring the pilot.