Incident Overview
After a normal touchdown, the right forward support tube on the nose actuator attach foot failed due to a fatigue crack at the weld joint. This failure caused the airplane to veer to the right, which then resulted in an overstress fracture of the left forward support tube on the nose actuator attach foot. The partial collapse of the nose landing gear occurred as a consequence.
Pilot Actions and Outcome
The pilot was able to stop the airplane on the runway following the incident. No further movement or additional damage beyond the partial collapse was reported.
Maintenance History
Service Bulletin (SB) 1154A had been performed on the airplane 63.9 hours prior to the incident. This bulletin was issued by the airplane manufacturer due to previous failures of the engine mount at the actuator attach foot attach point. The SB requires repetitive inspections every 100 hours of time in service unless a newly designed engine mount is installed.
Technical Details
The fatigue crack initiated at the weld joint of the right forward support tube on the nose actuator attach foot. The subsequent overstress fracture of the left forward support tube occurred as the airplane veered, leading to the partial collapse of the nose landing gear. No other components or structures were specified as damaged.
Conclusion
The incident was the result of a fatigue crack in the weld joint of the right forward support tube, which precipitated a chain of failures. The applicable service bulletin was complied with, but the inspection interval had not yet been reached at the time of the event.