As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PART OF IGNITER PLUG THAT SURROUNDS ELECTRODE SEPARATES AND SHORTS AGAINST THE ELECTRODE CAUSING THE APU NOT TO START. PART COULD POSSIBLY ENTER THE COMBUSTION AREA OF THE APU. (NOTE: APU HAS ONE IGNITER, WE HAVE HAD 2 RECENT FAILURES). (K)