What was found
CORROSION AT CTR WING TANK LWR SURFACE, INSIDE RT A/C BAY PLENUM, APPROX BS 830. REMOVED FASTENERS FOR ACCESS AS PER B727 SRM 51-30-2. REMOVED RT PRIMARY AND SECONDARY HEAT EXCHANGER AND PLENUM ASSY FOR SM ACCESS B727 MM 21-50-21. REMOVED CORROSION AT CTR WING TANK LOWER SURFACE I/B A/C PLENUM FROM STA 830 TO 839 RBL 32 TO 23 INCHES AS PER B727 SRM 51-10- 6. PERFORMED HFEC INSPECTION AT AREA PER NDT PART 6,51-00-00 FIG 4. NO DEFECTS NOTED. PERFORMED THICKNESS CHECK OF LOWER SKIN BS 830 TO 839.0 RBL 32 TO 23 PER PANAMETRICS MANUAL 910-131B, LOWEST READINGS .109,SEVERAL AREAS OUT OF LIMITS. REMOVED INTERNAL DOUBLER RBL 32 TO RBL 13 STA 830 AS PER B727 SRM 51-30-2.