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 & Y=+260.4. THE APPROX DAMAGE DIMENSIONS ARE AS FOLLOWS, AREA 1 – 1.10 INCHES X 0.95 INCH TO A MAX DEPTH OF 0.031 INCH. AREA 2 – 2.00 INCHES X 1.15 INCHES TO A MAX DEPTH OF 0.028 INCH. AREA 3 – 0.40 INCH X 0.35 INCH TO A MAX DEPTH OF 0.080 INCH. AREA 4 – 1.00 INCH X 0.30 INCH TO A MAX DEPTH OF 0.065 INCH. 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 E170-53MR-028.1 WILL BE ISSUED TO ACCOMPLISH THE FOLLOW UP INSPECTIONS IAW ANAC DER FORM ATTACHED. REF TASK 53-23-005-0001, INTERNAL GVI THRESHOLD OF 20,483 FC OR 27,242 FH, INTERVAL OF 10,133 FC OR 13,476 FH, IS SUFFICIENT & IS MET USING THE INSPECTION REQUIREMENTS, MPG & MRBR REVISION 11. ACCOMPLISHMENT OF THIS MAJOR REPAIR WAS ON EO E170-53MR-028 UNDER WO 2039368.