As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A ROUTINE PERIODIC INSPECTION A CRACK WAS FOUND IN VERTICAL STABILIZER BOTTOM RIB (PN 410008197) . THE CRACK RADIATED FROM THE SIDE FLANGE (LEFT) FORWARD RIVET AND EXTENDED TO THE EDGE OF THE RIB. THE TOTAL CRACK LENGTH IS .375 INCH. THE LOWER RIB OF THE VERTICAL STABILIZER SEEMS TO BE A CRACK PRONE AREA .