What was found
CORROSION WAS FOUND ON UPPER SURFACE OF CABIN FLOOR BEAM UPPER CHORD STATION 312 RBL 11 STRINGER 0.5, 0.5 INCHES. BLENDED OUT DAMAGE IAW SRM 51-10-02, REMOVED AFFECTED FASTENERS IAW NDT PART6 51-00-00. PERFORMED HFEC INSPECTION TO REWORKED AREA SRM 51-40-02, DONE 10X MAGNIFIED DIV REWORKED AREA TO ENSURE EA NO CRACK INDICATION. MEASURED THE ORIGINAL THICKNESS, INSPECTED THE HOLES NO CRACK INDICATION. IAW SRM 51-20-06 PERFORMS STRINGER =0.130 INCHES. REMOVED THICKNESS X=0.033 INCHES, X T=25.4% THE SRM ALLOWABLE HOT PEENING INTENSITY 0.005-0.010 INCHES, MADE REPAIR STRAP USE LE. MAX REMOVAL 10%T 1T EXCEED THIS LIMIT IAW SRM 53-10-51. 0.071 INCHES THICK 7075-T6 CLAD SHEET PER ECRA5321-01885. MADE TAPERED SHIM USE 0.071 INCHES THICK 7075-T6 CLAD SHEET IAW ECRA 5321-01885. FILLED BLENDED AREA IAW ECRA 5321-01885. INSTALLED COUNTERSINK REPAIR WASHERS & REPAIR PARTS IAW ECRA5321-01885. APPLIED CIC TO REPAIR AREA IAW ECRA5100-01844.