What was found
DURING HEAVY MX CHECK, FOUND LT WING CORROSION ON LOWER WING SURFACE OTBD OF NR 1 SPOILER ACTUATOR FITTING ABOVE FALSE SPAR. REMOVED FASTENER AND REMOVED CORROSION BY BLENDING. ACCOMPLISHED HFEC AND INSTALL THE REPLACEMENT OVERSIZE FASTENERES IAW SRM 51-76-11, 51-76-12, 51-42-11, AND 51-43-00. COMPLIED WITH EC A13-554-01.