What was found
CORROSION FWD DRAIN MAST AFT ANGLE SUPPORT, INTERNAL SIDE OF FUSELAGE BETWEEN FR16-17, STR 26R-27R. REMOVED AND INSTALLED NEW FWD DRAIN MAST AFT SUPPORT ANGLE REF SRM SRM 51-43-03, 51-41-02, 51-41-01. PN 170-08185-001. AIRCRAFT REMAINS IN HEAVY CHECK BNA.