What was found
ON 26 SEPT, DURING A PATIENT TRANSPORT FLIGHT, THE PILOT REPORTED CRITICALLY LOW VOLTAGE, ALL ELECTRONICS LOST AND MADE A PRECAUTIONARY LANDING WITHOUT FURTHER INCIDENT. BASE MECHANIC ARRIVED ON SCENE, CHECKED, & DETERMINED THAT BATTERY FAILURE WAS NOT AN ISSUE, THE BATTERY HAD LESS THAN 70 HRS SINCE NEW. REMOVED THE STARTER/GENERATOR & INSPECTED THE BRUSHES. HE FOUND SIGNIFICANT WEAR. HE ALSO FOUND THE COMMUTATOR BLACKENED. A BASE MECHANIC HAD JUST INSPECTED THE BRUSHES ON 19 SEPT, IN ACCORDANCE WITH THE MANUFACTURER'S ICA, AND THE BRUSHES HAD ALMOST ALL OF THEIR LIFE REMAINING AT THAT TIME. THE RESPONDING MECHANIC INSTALLED AN OVERHAULED S/G AND THE HELICOPTER RETURNED TO SERVICE WITHOUT FURTHER INCIDENT.