As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE A/C WAS IN FOR HEAVY MAINT. FOUND RT SIDE OUTBOARD RIB CRACKED ON HORIZ STAB AT FWD UPPER FLANGE RADIUS, 3/4" LONG. MX LOCATED AND DRILLED REPAIR ANGLE INSTALLED REPAIR ANGLE TO RIB P/N 85517473-102 IAW Q400 SRM 51-40-07, 55-10-10. A/C REMAINS IN TUS FOR COMPLETION.