On September 30, 2007, a Bellanca 7GCBC (registration N41695) was involved in an aviation accident near Laurel, MT. Investigators recorded the probable cause as: Corrosion-induced fatigue fracture of the left main landing gear due to a spot-welded step, with no documentation of the welding in maintenance records. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During an instructional flight, the left main landing gear assembly broke during rollout after a normal landing. Examination revealed a spot-welded step on the gear, with corrosion-induced fatigue fracture. No maintenance records for the welding were found.
Incident Overview
During an instructional flight, the left main landing gear assembly failed during the rollout phase following a normal landing. The gear assembly broke and separated from the aircraft.
Investigation
An examination of the failed left main landing gear assembly was conducted. It revealed that a step had been spot welded onto the gear assembly. Over time, corrosion developed in the vicinity of the weld. The corrosion led to fatigue cracking, and the gear eventually fractured due to corrosion-induced fatigue and separated.
Maintenance History
A review of the aircraft's maintenance records found no evidence of gear maintenance specific to the welding of the step onto the gear assembly. This indicates that the welding was not recorded as part of any documented maintenance activity.
Probable cause
Corrosion-induced fatigue fracture of the left main landing gear due to a spot-welded step, with no documentation of the welding in maintenance records.