What was found
DURING HEAVY CHECK, FWD FUSELAGE FLOOR STRUCTURE AT FRAME 19 IS CORRODED. MAINTENANCE R & R LT INBD FF SEAT TRACK EXTENSION IAW SRM 51-40-02, 51-43-01, 51-43-02 RESTORED TOPCOAT AND CIC IAW 51-25-00. PN 170-03264-001 TRACK. AIRCRAFT REMAINS UNTIL HEAVY CHECK IS COMPLETED.