Accident Details
The airplane sustained substantial damage when the left main landing gear torque links separated during landing. The aircraft subsequently departed the left side of the runway and came to rest approximately 1,250 feet from the approach end. A skid mark began about 400 feet from the end of the runway, left of the runway centerline. The mark initially appeared as a straight skid mark before transitioning to a weaving or wavy pattern that extended approximately 60 feet.
Examination Findings
Examination of the airframe revealed that the left main landing gear torque links had separated at the center hinge point, and the wheel assembly was rotated 180 degrees. The washers installed under the bolt head at the pivot hinge did not conform to the washers specified by the airframe manufacturer's maintenance manual and service bulletin. The installed washer outside diameter measured approximately 0.560 inch, while the through hole in the torque links measured 0.562 inch. The specified washers had an outside diameter of 0.750 inch. The undersized washers allowed the bolt and bushing stack-up to pull through the upper torque link, freeing the lower landing gear strut and wheel assembly to rotate out of alignment with the upper strut.
Maintenance History
Review of the aircraft maintenance records revealed that new torque link shafts and bearings were installed on the left main landing gear assembly in August 2000, at 3,060 hours total airframe time. The most recent annual inspection was completed on February 14, 2006, at 3,316 hours total airframe time. An entry noting compliance with the service bulletin was not observed in the maintenance log.