What was found
(CAN) DURING PHASE 3 INSPECTIONS, CABIN FLOOR SEAT TRACK SUPPORT BULKHEADS WERE FOUND CRACKED AT LT & RT FS 246.75 AND FS 265.75. SIRM CH 53-00-11-201 STATES STANDARD REPAIRS FOR CRACKS FOUND IN THESE FLOOR STRUCTURES. HOWEVER, RT FS 246.75 INITIAL CRACK FOUND WAS .2500" GREATER THAN ALLOWED SIRM LIMITS. PERIMETER AVIATION ENGINEERING DAR WAS CONTACTED TO CREATE A REPAIR FOR THE BEYOND LIMIT CRACK. DURING THE REQUIRED NDT OF REPAIR AREA CUT-OUT, AND A SECOND CRACK WAS FOUND BY EDDY CURRENT NDT. THE SECOND CRACK WAS COMING FROM A RIVET HOLE THAT WAS IN THE SECOND COLUMN OF RIVET HOLES OTBD OF RBL 23.42, AND THE SECOND RIVET HOLE FROM TOP OF WL 87.00. SEE FIG 203 OF SIRM 53-00-11-201.