On September 13, 1997, a Cessna 411 (registration N12WT) was involved in an aviation accident near Williston, FL. Investigators recorded the probable cause as: Failure of the side brace lock bolt due to shear, which resulted in the collapse of the left main landing gear. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
While executing a 130-degree right turn off the runway at a speed described by witnesses as 'a little fast', the left main landing gear of an aircraft collapsed. Investigation revealed the side brace lock bolt failed in shear.
Incident Description
During an attempted 130-degree change in direction to the right off the runway, the left main landing gear collapsed. Witnesses reported that the aircraft was traveling at a speed they described as 'a little fast' at the time of the maneuver.
Examination Findings
Post-incident examination of the left main landing gear assembly revealed that the side brace lock bolt had failed. Metallurgical analysis determined that the bolt failed due to shear stress. Hardness testing of the failed bolt indicated that its hardness was within acceptable limits. The bolt had been installed 3.0 flight hours prior to the incident, during the most recent annual inspection.
Probable cause
Failure of the side brace lock bolt due to shear, which resulted in the collapse of the left main landing gear.