What was found
THIS EO IS BEING ISSUED TO PROVIDE INSTRUCTIONS TO ACCOMPLISH THE PERMANENT REPAIR OF CORROSION DAMAGE TO THE FWD CABIN FLOOR STRUCTURE LT FWD SEAT TRACK, PN 170-03264-001 AT CROSSBEAM FRAME 16 & 19. THE APPROX DAMAGE DIMENSIONS ARE AS FOLLOWS, 1.5 INCHES X 1.0 INCH TO A MAXIMUM DEPTH OF .031 INCH DEEP & 1.30 INCHES X 1.0 INCH TO A MAXIMUM DEPTH OF .046 INCH DEEP. THE CORROSION DAMAGED EXISTING REPAIR DOUBLER LOCATED AT FRAME 19 WAS INSTALLED IAW EO E175-53-015. REMOVED THE EXISTING DOUBLER & NOTED NO ADDITIONAL TRACK DAMAGE FOUND UNDER THE DOUBLER. THE LT SEAT TRACK IS NOT CLASSIFIED AS FATIGUE CRITICAL STRUCTURE, FCS, IN FCSD-3575, BUT IS CLASSIFIED AS PRIMARY STRUCTURE IN SRM PART II 51-00-04. ACCOMPLISHMENT OF THIS EO HAS BEEN CLASSIFIED AS A MAJOR REPAIR DUE TO STRENGTH RESTORATION OF PRIMARY STRUCTURE. SUPPLEMENTAL FOLLOW UP INSPECTIONS ARE NOT REQUIRED IAW SRM PART II 53-10-10 REPAIR 01P. ACCOMPLISHMENT OF THIS MAJOR REPAIR IS ON EO E175-53MR-193 UNDER WO 1923889.