What was found
DURING HEAVY CHECK LT HORIZONTAL STABILIZER, RIB 11 IS CRACKED 5-6 RIVETS BACK FROM FORWARD SPAR UPPER SKIN ATTACH POINT. MAINTENANCE REPAIRED RIBS 11A, 12A IAW ETD 2016-170-034759 CUTOUT CRACKED FLANGES FABRICATED AND INSTALLED SHEAR CLIPS.