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SZD-24-4A Foka 4, G-DBZZ

Date of occurrence: 08 August 2010

Summary:
During the second winch launch of the day, the wings of the glider separated from the fuselage. The pilot sustained fatal injuries in the resulting impact. The investigation determined that when the aircraft was rigged, the lower bevel bolt of the wing main fitting had not fully engaged with the lower lug stack of the main spar joint and it was not possible to detect this condition. As a consequence, when the glider became airborne, the partially secured joint was unable to sustain the wing bending moments associated with the winch launch and the lower bevel bolt failed. This allowed the lower attachment lugs to disengage and the wings to fold upwards and separate from the fuselage. Two safety recommendations have been made as a result of the investigation.

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Report name:
SZD-24-4A Foka 4, G-DBZZ
Registration:
G-DBZZ
Type:
SZD-24-4A Foka 4
Location:
Bicester Airfield, Oxfordshire
Date of occurrence:
08 August 2010
Category:
Sport Aviation/Balloons
Summary:
During the second winch launch of the day, the wings of the glider separated from the fuselage. The pilot sustained fatal injuries in the resulting impact. The investigation determined that when the aircraft was rigged, the lower bevel bolt of the wing main fitting had not fully engaged with the lower lug stack of the main spar joint and it was not possible to detect this condition. As a consequence, when the glider became airborne, the partially secured joint was unable to sustain the wing bending moments associated with the winch launch and the lower bevel bolt failed. This allowed the lower attachment lugs to disengage and the wings to fold upwards and separate from the fuselage. Two safety recommendations have been made as a result of the investigation.
Download report:
PDF icon SZD-24-4A Foka 4, G-DBZZ 05-11.pdf (1,552.57 kb)