What happened
During the landing roll, the right main landing gear collapsed. Following this structural failure, the airplane veered sharply to the right, resulting in the right wing striking a runway light.
The investigation
A post-accident examination of the aircraft revealed that the failure originated from the landing gear trunnion located on the lower fillet of the web. A detailed metallurgical analysis determined that the trunnion suffered from fatigue failure. The root cause was traced to grinding marks present on the component, which were introduced during the manufacturing finishing process.
Findings
The investigation identified fatigue failure of the landing gear trunnion as the primary mechanical issue. These findings highlight a critical manufacturing defect that compromised the structural integrity of the gear. It is noted that the manufacturer had issued a service bulletin in 1985 specifically addressing the inspection of this area for cracks, indicating prior awareness of this vulnerability.