On September 5, 1999, a Cessna 190 (registration N9872A) was involved in an aviation accident near Enterprise, AL. Investigators recorded the probable cause as: The fatigue failure of the main landing gear spring. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During the landing rollout, the left main landing gear spring leaf assembly separated from the airframe due to a preexisting fracture with evidence of fatigue cracking and fretting damage.
Accident Description
After approximately one hour of pleasure flying in the local flying area, the two pilots returned to the departure airport for a full-stop landing. After touchdown, the airplane had rolled several hundred feet when the pilot felt an unusual sensation in the airframe. At approximately the same time, the left spring leaf landing gear assembly separated from the airframe, and the airplane fell to the ground.
Examination Findings
A field examination of the fracture face disclosed evidence of a preexisting fracture in the steel material. Follow-up examination of the fracture face with the aid of a bench binocular microscope revealed the presence of at least three small fracture areas typical of fatigue cracking. The origin of the fatigue cracking was damaged during the ultimate separation. The examination also disclosed that the fatigue origin was located in an area that showed fretting damage.