Incident Overview
According to the pilot, after four parachutists boarded the airplane, the taxi began from the gate. The airplane traveled approximately 25 yards on upward sloping grass terrain when the right main landing gear collapsed.
Examination Findings
Examination of the landing gear revealed a break approximately 10 inches from the inboard end of the landing gear leg, at the point where it is clamped to the fuselage structure. No other anomalies were found on the airplane.
Laboratory Analysis
The Materials Laboratory Division of the National Transportation Safety Board examined the landing gear. The analysis indicated that the break stemmed from preexisting fatigue regions located on the lower forward surface of the landing gear leg. This area also contained evidence of fretting damage in regions where paint had been lost.
Conclusion
The landing gear failure was attributed to preexisting fatigue and fretting damage.