Incident Overview
During the second touch-and-go landing at an airstrip, the pilot reported that approximately halfway down the runway, the left wheel separated from the airplane, causing it to nose over. Surface tracks indicated that the airplane had been traveling along the runway centerline and continued for an additional 30 yards after the wheel separation before nosing over.
Examination Findings
Federal Aviation Administration (FAA) inspectors observed that the left wheel and gear extension had detached from the left main landing gear leg. The separated components were found off the left side of the runway. The National Transportation Safety Board (NTSB) materials laboratory examined the four attachment bolts from the left main landing gear extension. All four bolts were found to be bent through their shank portions, but none were fully separated. The threads on each bolt showed scraping on the convex side of the bend, consistent with sliding out of the bolt hole. Three of the four bolts exhibited what appeared to be stripped threads from their corresponding nuts lodged in the thread grooves. No evidence of a nut was found on the fourth bolt.
Inspection History
Records indicated that the airplane had undergone an annual inspection on November 11, 1999, and had accumulated seven hours of operation since that inspection.