Incident Overview
An aircraft experienced a structural failure during the climb-out phase after takeoff, approximately 200 feet above ground level. The left wing folded upward just outboard of the lift strut wing attach points. The aircraft then entered a vertical descent, with the wing section trailing behind, remaining attached by what one witness believed were the control cables. The descent continued until the aircraft collided with the ground.
Structural Examination
During the descent, the forward left wing lift strut separated. Subsequent examination of the left side forward and aft lift strut attach fittings and fork assemblies was conducted by an NTSB metallurgist. The metallurgist reported that all fracture features and deformation were typical of overstress fractures under bending load.
Maintenance History
Historical maintenance documentation revealed that the pilot, who was not a certified mechanic, had been performing extensive structural maintenance on the aircraft since the late 1970s. This work was then signed off by a certified mechanic.