What was found
DURING C-CHECK, WING CENTER SECTION LOWER SKIN CORRODED ABOVE RT PRIMARY HEAT EXCHANGER. REMOVED CORROSION IAW B-727 SRM 51-10-6 WITH A MAT LOSS OF .057 AREAS FOUND TO BE OUT OF LIMITS IAW B-727 SRM 57-30-1 FIG 4 TABLE I FIG 5, PARA 2 FABBED DOUBLER FROM 2024 T3 .080 PO 900103 DIM 16.25 X 14.5 INCH AND TRIPLER FROM SAME MATERIAL DIM 14.375 X 13.5 INCH IAW B-727 SRM 57-30-3 FIG 8, 9 & 10. PARTS TREATED AND PRIMED IAW B-727 SRM 51-10-2 AND INSTALLED IAW B-727 SRM 57-30-3 FIG 8, 9 & 10. REMOVED AND RE-INSTALLED RT PRIMARY HEAT EXCHANGER IAW B-727 MM 21-55-21. OP'S AND LEAKED CHECK GOOD IAW B-727 MM 21-00 AND FUEL LEAK CHECK GOOD IAW B-727 MM 28-11-0.