Accident Description
During the landing roll, the nose gear of the aircraft collapsed, resulting in substantial damage to the airframe. The incident occurred after the aircraft had touched down and was decelerating on the runway.
Maintenance History
The nose gear retraction-extension mechanism had been a recurring maintenance issue. It was serviced immediately prior to this flight and on several other occasions due to its failure to properly extend or retract. Despite these efforts, the mechanism continued to malfunction.
Investigation Findings
Following the accident, a detailed examination of the nose gear assembly was performed. Investigators found that the overcenter locking mechanism was dirty and gummy. This contamination interfered with the proper function of the mechanism, preventing hydraulic pressure from fully extending the nose gear. As a result, the nose gear was not locked in the extended position during landing, leading to its collapse.
Post-Accident Testing
After the overcenter locking mechanism was thoroughly cleaned, it was tested and found to operate normally. This verified that the contamination was the direct cause of the failure.