What happened
Following the completion of the landing roll, the aircraft moved from the runway onto the taxiway. As it was exiting onto the taxiway, the left main landing gear suddenly collapsed. The failure occurred after the aircraft had already touched down and was in the process of transitioning to ground operations.
The investigation
A detailed metallurgical examination was conducted on the components of the failed landing gear assembly. Investigators focused on the broken down lock hook, link, fitting, and pin. The analysis revealed fractures that were characteristic of an overstress separation, indicating that the components failed due to excessive load rather than fatigue or material defects.
Findings
The examination determined that the root cause of the collapse was mechanical in nature. Specifically, the down lock hook did not properly engage the lock plate on the drag link. This lack of engagement prevented the gear from remaining in the extended position under load. The failure to engage was attributed to either inadequate rigging of the mechanism or excessive binding of the fitting, which hindered proper operation.