What was found
AFTER COMPLETING BEFORE START CHECKLIST EXTERNAL POWER WENT OFF LINE AND CABIN FILLED WITH SMOKE. MTC DEFERRED ENTIRE APU.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
AFTER COMPLETING BEFORE START CHECKLIST EXTERNAL POWER WENT OFF LINE AND CABIN FILLED WITH SMOKE. MTC DEFERRED ENTIRE APU.