What was found
WHILE ACFT IN HEAVY CHECK MAINT FOUND FORWARD RT SILL FR12-FR14 HAS CORROSION, REMOVED AND REPLACED SILL REF SRM 51-40-08. RESTORED SURFACE PROTECTION REF SRM 51-10-04, 51-10-05, AND 51-10-06. ACFT REMAINS IN HEAVY CHECK UNTIL COMPLETION.