Incident
During a night cross-country flight, the airplane experienced a complete loss of electrical power. In response, the pilot elected to conduct a precautionary landing at a nearby airport. On the final approach segment, the pilot could not locate his flashlight. The pilot reported that the airplane contacted the runway earlier than he had expected. The pilot's most recent night flying in that airplane had taken place four months prior. Additionally, the pilot noted that he had never performed a night landing without the aid of instrument or cockpit lighting, as he relied on those systems. The lack of electrical power rendered the cockpit lights and instruments inoperative, creating challenging conditions for the pilot.
Investigation
Following the event, an inspection was performed on the airplane's electrical system. The alternator was found to be incapable of producing a charge. Further examination revealed that the alternator's commutator brushes and their mounts were worn beyond the manufacturer's allowable tolerances. The commutator surface was coated with a black, oily residue, and black dust had accumulated on the brush mounts and portions of the commutator. These conditions likely prevented the alternator from generating electrical power, leading to the battery draining and the total electrical failure.
The investigation did not assign a formal probable cause, but documented the pilot's statements regarding his recent night experience and his usual reliance on cockpit lighting during night operations. The condition of the alternator components was noted as a significant mechanical issue.