What was found
WHILE AC WAS IN FOR HEAVY CHECK FOUND AFT CABIN FLOOR AT FR 90 LBL 10 HAS CORRODED PLATE WITH SHEARED RIVETS. MX REMOVED AND REPLACED AFT CABIN FLOOR GUSSET PLATE AT FR 90 LBL 10 PN 170-60257-001 IAW SRM 51-75-16, 53-30-10, 51-40-02, 51-40-08. AC REMAINS IN IND FOR COMPLETION.