What was found
THIS EO IS BEING ISSUED TO PROVIDE INSTRUCTIONS TO ACCOMPLISH THE PERMANENT REPAIR OF CORROSION DAMAGE TO THE AFT CABIN FLOOR STRUCTURE, RT AFT SEAT TRACK PN 170-86082-003 AT FRAME 84. THE APPROX DAMAGE DIMENSIONS ARE AS FOLLOWS. 3.4 INCHES X 1.10 INCHES TO A MAXIMUM DEPTH OF .029 INCH DEEP. 3.30 INCHES X .40 INCH DEEP TO A MAXIMUM DEPTH OF .060 INCH DEEP. BECAUSE THE FLOOR TRACK IS A PSE, ACCOMPLISHMENT OF THIS EO HAS BEEN CLASSIFIED AS A MAJOR REPAIR DUE TO STRENGTH RESTORATION. THIS IS NOT CLASSIFIED AS FCS, BUT WILL REQUIRE FOLLOW UP INSPECTIONS. EO E175-53MR-233 1 WILL BE ISSUED TO ACCOMPLISH THE FOLLOW UP INSPECTIONS IAW ANAC DER FORM ATTACHED. TASK 53-23-005-0001, INTERNAL GVI THRESHOLD OF 20,483FC OR 27,242FH, INTERVAL OF 10,133FC OR 13,476FH, IS SUFFICIENT & IS MET USING THE INSPECTION REQUIREMENTS, MPG & MRBR REVISION 11. ACCOMPLISHMENT OF THIS MAJOR REPAIR WAS ON EO E175-53MR-233 UNDER WO 2004864.