Incident Overview
A pilot operating under visual flight rules (VFR) conducted a visual approach to Runway 06. According to the pilot's account, the landing was described as "a little bumpier than some, but not a hard landing," and the airplane "ballooned" before its final touchdown.
Landing Gear Failure
Following the final touchdown, the right main landing gear collapsed, and the airplane veered off the side of the runway. An examination of the landing gear revealed a fracture in the web area of the trunnion.
Relevant Directives and Service Bulletins
An Airworthiness Directive (AD) and a service bulletin from the manufacturer had called for inspection of the web area for cracks, stating: "To prevent collapse of the main landing gear caused by cracked trunnions, which could result in airplane damage."
Metallurgical Findings
A detailed metallurgical examination of the landing gear determined that the fractures were due to overstress. No pre-existing fractures were observed in the trunnion.
Conclusion
The investigation did not provide a single stated cause for the event, but the overstress fractures were identified as the immediate technical failure.