What was found
LT FWD SILL FR 12-16 LBL 43"-49" HAS CORROSION (100%) AT FR 16. REMOVED AND REPLACED 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 398 FOR WORK DETAILS. AIRCRAFT REMAINS IN HEAVY CHECK BNA.