What was found
FWD RT SILL (FLOOR) FR 12-14 RBL 36"- RBL 49" HAS CORROSION IN 2 LOCATIONS AT FASTENER HOLE FR 14 AND INBD/AFT CORNER OF SHEET; FR14 . REMOVED AND REPLACED RT SILL REF. SRM 51-40-08. RESTORED SURFACE PROTECTION REF. SRM 51-23-04, 51-23-05, AND 51-23-06. SEE W/O H6609 SN 412 FOR WORK DETAILS. AIRCRAFT REMAINS IN HEAVY CHECK BNA.