What was found
MCN - MAJOR REPAIR - DURING C-04 CHECK FILIFORM CORROSION WAS FOUND ON UPPER SURFACE OF RT OUTBOARD CABIN SEAT TRACK FORWARD END AT FR 20. MAINTENANCE REMOVED CORROSION AND FOUND MATERIAL LOSS TO BE OUT OF LIMITS. REMOVED RT OUTBOARD CABIN SEAT TRACK FORWARD END AT FR 20; FABRICATED A NEW REPLACEMENT SEAT TRACK; INSTALLED REPAIR PART IAW A320 SRM 51-44-11 PG 1, 19, & 20, FIG 2, AND SRM 51-42-11 PG 1, 7, 21, 22, 28, & 39, FIG 8 & 12.