Accident
During the takeoff roll, the airplane swerved uncontrollably to the left, departed the runway, and went down an embankment. The nose landing gear partially collapsed, making directional control impossible.
Investigation
Post-accident investigation disclosed a fracture of the nose landing gear strut where it attaches to the engine mount. The fracture area had been welded as part of a repair to the engine mount during an annual inspection.
Metallurgical Findings
According to a National Transportation Safety Board (NTSB) metallurgical report, examination of the fracture revealed numerous weld defects, including poor fusion, excessive porosity, and voids. Additionally, the metal in the weld area was found to be significantly softer than the surrounding metal.