What was found
DURING BASIC CHECK, INSPECTION DISCOVERED CORROSION ON THE AFT CABIN LT AFT BEAM, PN 170-65669-003, UPPER FLANGE. REQUESTED A REPAIR & RECEIVED ETD2015-170-115477A WHICH PROVIDES A PERMANENT REPAIR BY INSTALLING A REPAIR DOUBLER USING THE PRINCIPLES OF SRM PART II 53-23-10 REPAIR 02P. THE CORROSION DAMAGE APPROX DIMENSIONS ARE 1.0 INCH X .50 INCH WITH 100% MATERIAL LOSS IN THE DEEPEST LOCATION. ENGINEERING HAS CLASSIFIED THIS REPAIR AS A MAJOR REPAIR. THIS STRUCTURE IS NOT FCS, BUT REQUIRES FOLLOW UP INSPECTIONS. EO E175-53MR-228.1 WILL BE ISSUED TO ACCOMPLISH FOLLOW UP INSPECTIONS IAW ETD2015-170-115477A ANAC DER FORM ATTACHED. REF INSPECTION INSTRUCTIONS 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. THRESHOLD IS COUNTED SINCE NEW. ACCOMPLISHMENT OF THIS MAJOR REPAIR IS ON EO E175-53MR-228 UNDER WO 1997367.