As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI FROM THE OPERATOR`S HOME BASE AND PRIOR TO A SCHEDULED DEPARTURE, THE RT AC ELECTRICAL SYSTEM FAILED. THE AIRCRAFT RETURNED TO BASE, THE SYSTEM WAS TROUBLESHOT AND THE RT AC CONVERTER WAS FOUND TO BE FAULTY. THE UNIT WAS REPLACED WITH A SERVICABLE PART AND THE AIRCRAFT WAS RETURNED TO AIRWORTHY CONDITION. THIS UNIT HAS PROVEN TO BE VERY UNRELIABLE. SINCE IT'S CONSIDERED TO BE DISPATCH CRITICAL, WE BELIEVE THAT THE FAA AND THE MANUFACTURER NEED TO FULLY INVESTIGATE THIS MATTER.