Incident Description
During a precautionary landing prompted by electrical problems, the airplane's main landing gear collapsed. The pilot had initiated the landing after experiencing electrical issues, and the landing gear failed to remain extended upon touchdown.
Witness and Pilot Statements
A witness observed that the main landing gear was not fully extended during the approach to the landing runway. The pilot reported lowering the landing gear handle, and the extension sequence appeared normal. However, at that point the electrical system seemed dead, and no green 'gear down' indicator light was observed. The pilot noted that a hand-operated hydraulic pump is available in the aircraft for extending the landing gear in case of hydraulic or electrical system failure, but it is not stated whether the pilot attempted to use it.
Post-Accident Inspection
Following the accident, the alternator circuit breaker was found in the out (tripped) position. The landing gear was cycled multiple times, and no anomalies were detected during these tests. The gear functioned normally when tested after the incident.
Subsystems and Mechanisms
The airplane is equipped with a hand-operated hydraulic pump intended to extend the landing gear if the primary hydraulic or electrical systems fail. The landing gear extension sequence relies on electrical power to confirm down-lock via a green indicator light. The absence of this light, combined with the dead electrical system, likely contributed to the pilot's inability to verify proper gear extension.