What was found
DURING BASIC CHECK, INSPECTION DISCOVERED CORROSION ON THE AFT CABIN CROSSBEAM FRAME 87, PN 170-86056-003, UPPER FLANGE LOCATED APPROX AT Y=-260.4. REQUESTED A REPAIR & RECEIVED ETD2015-170-091494 WHICH PROVIDES A PERMANENT REPAIR BY INSTALLING A REPAIR NESTED ANGLE IAW ETD2015-170-091494. THE CORROSION DAMAGE APPROX DIMENSIONS ARE .60 INCH X .80 INCH TO A MAXIMUM DEPTH OF .039 INCH DEEP, REF FIGURES 1 & 2. ENGINEERING HAS CLASSIFIED THIS REPAIR AS A MAJOR REPAIR. THIS STRUCTURE IS PSE & FCS, & REQUIRES FOLLOW UP INSPECTIONS. EO E175-53MR-216.1 WILL BE ISSUED TO ACCOMPLISH FOLLOW UP INSPECTIONS IAW ETD2015-170-091494 ANAC DER FORM ATTACHED. REF TASK 53-23-005-0001, INTERNAL GVI THRESHOLD OF 20,000 FC OR 26,600 FH, INTERVAL OF 5,099 FC OR 6,781FH, IS SUFFICIENT & IS MET USING THE INSPECTION REQUIREMENTS, MPG & MRBR REVISION 11. THRESHOLD IS COUNTED SINCE NEW. ACCOMPLISHMENT OF THIS MAJOR REPAIR WAS ON EO E175-53MR-216, WO 1965913.