What happened
The pilot reported conducting a standard approach to runway 12. During the landing rollout, as the nose of the aircraft made contact with the ground, the nose gear assembly collapsed. The aircraft subsequently slid to a stop.
The investigation
Post-crash examination of the aircraft revealed that the green light for the nose gear remained illuminated regardless of the actual landing gear position. This malfunction was caused by a broken lead wire on the number 5 pole of the nose landing gear position micro switch.
This specific micro switch is responsible for activating the hydraulic pressure that holds the gear in the locked position. Consequently, the pilot received a down and locked indication even though the gear was not actually locked in the down position.
Findings
The primary factor was the failure of the nose landing gear to lock due to the broken lead wire on the micro switch. This resulted in a false indication to the pilot that the gear was secure, leading to the collapse upon touchdown.