As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MCN - MAJOR REPAIR - DURING C-04 CHECK GALVANIC CORROSION WAS FOUND ON UPPER SURFACE OF FLOORBEAM Y-919 AT FORWARD SIDE OF FR 66. MAINTENANCE REMOVED CORROSION AND FOUND MATERIAL LOSS TO BE WITHIN ALLOWABLE LIMITS PER AWA ER 26-5341-03105-SS1; TREATED, PRIMED AND TOP COATED BLENDED AREA IAW A320 SRM 51-21-11 PG 2-7.