Event Description
The pilot reported that the landing gear extension proceeded normally, with three green lights indicating all gear were down and locked. The gear warning horn was not activated, and the pilot confirmed the nose gear was extended by observing the nacelle mirror. After touchdown, as the nose was lowered to the runway, the nose gear collapsed.
Inspection and Testing
A preliminary inspection of the aircraft revealed no evidence of pre-impact mechanical or hydraulic malfunctions. A functional test of the nose gear actuator was requested, but the unit was overhauled instead. The overhauled actuator showed no signs of stress or abnormal wear and was subsequently approved for return to service.
Conclusion
Despite the normal indications and the lack of discovered mechanical deficiencies, the nose gear collapsed. The investigation was unable to determine the cause of the collapse.