What was found
HEAVY CHECK/MAJOR REPAIR, VALVE MOUNTING PLATE LOCATED BETWEEN FRAMES 18-19, STRINGER 21L-20R HAS AREAS OF LEVEL 2 CORROSION. AFFECTED AREAS LOCATED AT FWD AND AFT CORNERS BETWEEN STRINGERS 21L-21R. REPAIR PER SRAS ES-4429/16.10811 DATED 11/25/2016.