Event Description
The accident occurred during a landing sequence. The pilot reported that on the second touch-and-go landing, he felt a vibration and observed that the left main landing gear strut was trailing at approximately a 45-degree angle. In response, the pilot decided to land on the grass adjacent to the runway.
Pilot Actions and Outcome
Upon touchdown on the grass, the left main landing gear collapsed, causing the aircraft to nose down. The sequence of events was consistent with a loss of structural integrity in the landing gear.
Post-Accident Investigation
A post-accident investigation examined the landing gear components. It was determined that the attach bolt, identified by the part number Bellanca PN MS20007, had fractured. The National Transportation Safety Board (NTSB) laboratory analysis of the broken bolt revealed features typical of high-stress fatigue cracking over most of the fracture face. Additionally, two separate regions of fatigue cracking were noticeable on the fracture face, indicating a progressive failure mechanism.